Through the analysis of the work functions of "double-qualified" teachers, it is considered that "double-qualified" teachers should have "double-qualified skills", which can not only engage in teaching and academic research, but also undertake the practical work of engineering projects and solve practical engineering problems. In addition, you should also have a "double certificate", that is, on the one hand, you must have a lecturer's or above title and a teacher's qualification certificate, on the other hand, you must have an engineer's or above title or a national qualification certificate registered in this industry. Based on the above analysis, this paper puts forward the way to train "double-qualified" teachers based on "learning by doing".

Paper Keywords: Double-qualified teachers; Engineer; Doing middle school; reform in education

In order to cultivate students' professional skills and innovative ability and continuously improve the quality of education, higher vocational colleges must carry out deep-seated teaching reform. At present, the reform from experimental training conditions, curriculum system, training mode and teaching methods to students' learning methods, learning contents, training and practice methods is aimed at improving the quality of skilled talents. In these reforms, teachers are the link. Only when the reform of the teaching staff is successful can the educational effect be really significantly improved. Therefore, teacher reform is the key to teaching reform. The reform of teachers includes the construction of teachers and the reform of teachers, especially the reform of teachers. What kind of teacher is more suitable for training skilled talents? It is generally believed that "double-qualified" teachers are the most suitable. In recent years, the research on "double-qualified" teachers mainly focuses on two aspects. First, the construction of "double-qualified" teachers, such as: on the cultivation of "double-qualified" teachers in higher vocational colleges; The second is the training of "double-qualified" teachers, such as the exploration and practice of "double-qualified" teachers training mode in higher vocational colleges.

Because "double-qualified" teachers combine engineers' practical experience with teachers' professional knowledge, skills and accomplishment, they generally have strong teaching ability, scientific research ability and social service ability, can better complete teaching tasks and scientific research projects, and provide technical services for enterprises or society at the same time. Such teachers can integrate professional quality, professional knowledge, professional skills and innovative ability, and are the backbone of professional education. Therefore, most higher vocational colleges regard training "double-qualified" teachers as one of the important tasks of teacher reform.

First, the connotation of "double-qualified" teachers

There is no unified standard for "double-qualified" teachers at present. However, it is generally believed that "double-qualified" teachers should be teachers who can undertake both theoretical and practical teaching tasks and engineering project tasks, have deep theoretical basic knowledge and professional knowledge, have rich teaching experience and engineering practice experience, and generally should have teacher qualification certificate, intermediate or above professional title and engineering practice qualification certificate issued by the state or industry, and have strong innovation and scientific research ability. If a teacher only has certain professional theoretical knowledge, teaching experience and engineering practice experience, he can only be said to have a certain quality of dual-qualification, and can not be called a "dual-qualification" teacher. Similarly, if a teacher has the above qualifications, but lacks in teaching or engineering practice, or his teaching ability is not strong, or his engineering practice experience is insufficient, or both, he cannot be called a "double-qualified" teacher. In short, the connotation of "double-qualified" teachers: first, they have the teacher qualification certificate and the title of lecturer or above; Two, engineers, with relevant professional and technical title certificate or industry qualification certificate; Third, I have many years of actual combat experience and rich practical experience. In short, "double-qualified" teachers should include "double-qualified+double-qualified+double-qualified skills". They are both "teachers" and "engineers", who can not only engage in teaching and academic research, but also undertake practical work and solve practical engineering problems.

The second is the qualification of "double-qualified" teachers.

The qualifications of "double-qualified" teachers are determined by each school according to the relevant characteristics of different majors and industries. Take the major of architectural engineering technology as an example, a "double-qualified" teacher should obtain a "teacher qualification certificate" and hold the titles of "lecturer" and "engineer", that is, a "double certificate". If you don't have an engineer certificate, but you have more than one qualification certificate in the construction industry, such as "architect, structural engineer, consulting engineer, builder, supervision engineer or cost engineer" issued by the state in this industry, and you undertake the work in related professional fields, it is also considered to meet the requirements of "double certificates". Of course, the qualification of "double-qualified" teachers should also consider their work experience. Generally speaking, they should have more than three years of teaching experience and more than two years of engineering practice experience. They have not only engaged in theoretical and practical teaching, but also undertaken related engineering projects, with rich professional knowledge, strong innovation consciousness and practical ability.

Third, the basic ways to train "double-qualified" teachers

For a long time, the main problem that puzzles the quality of higher vocational education is how to cultivate high-quality and high-end skilled professionals that enterprises need. This is a topic that higher vocational colleges have been exploring, and some achievements have been made. Different colleges or majors have basically formed their own unique educational models and methods.

Taking the specialty of architectural engineering technology in ningbo polytechnic as an example, an educational model of "learning by doing, learning by doing and learning by doing" has been formed. The trained students can basically undertake the work of professional positions such as "builder" and are favored by cooperative enterprises. Many students are employed by enterprises in the internship stage, and even some students are directly sent to overseas engineering projects for internship and work. This shows that a solid step has been taken in how to cultivate the talents needed by enterprises. However, the quality of personnel training is still uneven, which still cannot meet the requirements of enterprise employment. Some students can't flexibly apply their professional skills and knowledge to practical projects, and even some of them are out of touch, so that many enterprises have to conduct secondary training for newly graduated students for a period of time before allowing them to work independently. The reason is that there are some problems in curriculum, teaching content, teaching methods, teachers' ability, students' learning attitude, learning methods and learning motivation, but the outstanding problem is that professional teachers have little engineering practice experience, professional skills and knowledge are difficult to combine with practical engineering application, and their comprehensive ability needs to be improved urgently.

Teaching practice has proved that the teaching quality of double-qualified and "double-qualified" teachers is obviously superior to other teachers, which has great attraction and promotion for students' learning. Therefore, it is very important to optimize the structure of teachers as soon as possible and improve their comprehensive ability, which plays a significant role in improving the quality of education. Generally speaking, the higher the proportion of "double-qualified" teachers, the higher the teaching level of the whole teaching team, and the stronger the scientific research ability and service ability. Then, how to improve teachers' comprehensive ability and train more "double-qualified" teachers? The key is to determine the appropriate ways and methods of culture.

1. Key teachers practice in enterprises to increase their engineering practice experience.

Due to the development of higher vocational colleges for many years, the teaching staff has been basically stable, and the cultivation of "double-qualified" teachers should be based on the existing teaching conditions, focusing on cultivating professional backbone teachers. Taking the specialty of construction engineering technology as an example, it is undoubtedly the most basic way to let teachers leave their posts to do first-line exercise or part-time work in construction enterprises, that is, to train "double-qualified" teachers on the basis of "learning by doing". Through "learning by doing", we can master new technologies, new processes, new materials and new equipment, combine professional knowledge and skills with engineering practice, and complete relevant post work to apply what we have learned. At the same time, teachers should also obtain the corresponding qualification certificates of "builder" and "supervision engineer" by taking the relevant professional qualification examinations held by the state, so as to lay a good foundation for participating in more engineering projects in the future. In this way, teachers can enrich their practical experience through "doing" projects, and also "learn" the latest technology and knowledge. In the teaching process, we can flexibly impart knowledge and skills to students with rich engineering project examples, so that "teaching", "learning" and "doing" can be integrated into one, forming a virtuous circle.