My understanding of educational technology can be divided into the following three aspects: (1) Educational technology is a carefully selected and reasonably organized learning textbook, which not only meets the needs of society and students' personal learning, but also conforms to the cognitive law and is suitable for students' learning. This is a software component of educational technology. (2) Educational technology is a variety of materialized means used in the educational process. From the most basic blackboard, chalk, text teaching materials, teaching AIDS, projectors, slide projectors, televisions, wired and wireless public address systems, video display tables to multimedia computers; CAW closed-circuit television teaching network system and computer bidirectional transmission interactive network system are both hardware components of educational technology. (3) Educational technology is also a method to design, implement and evaluate the teaching process. Such as Comenius' intuitive teaching method, Herbart's four-stage teaching method and the heuristic teaching method advocated by Confucius, an ancient educator in China. This is also an integral part of educational technology. From the perspective of teaching mode, modern educational technology teaching system is not only a teaching environment and system that can carry out personalized independent learning, but also a teaching environment and system that can form mutual cooperation. Whether it is the traditional audio-visual education means or the modern educational technology teaching system composed of multimedia teaching system, the diversity of input and output means makes it have strong interactive potential. Alternating the use of various learning forms can give full play to students' initiative in learning, thus completing autonomous learning. The multimedia teaching system combined with network technology can also enable students and teachers to communicate with each other across the limitations of time and space, and realize free discussion and collaborative learning, which is obviously incomparable to the traditional teaching mode. From the perspective of teaching law, modern educational technology overcomes the linear defect of traditional teaching knowledge structure, has the characteristics of multi-form and nonlinear network structure of information, and conforms to the cognitive law of modern education. First of all, the teaching system of modern educational technology is based on Quilling's semantic network theory in constructing and forming cognitive structure. Human cognition is a layer-by-layer network structure, including nodes, chains and so on. Nodes form a memory network through the action of chains. Starting from the initial knowledge node, the teaching structure of modern educational technology is a multi-level knowledge structure with a network-like knowledge chain structure. This is a kind of learning environment that organizes teaching information in the way of human thinking, and students can arrange their own learning environment according to their actual potential and learning needs. Obviously, the linearization of traditional teaching knowledge structure not only restricts the acquisition of multi-level and multi-angle knowledge information, but also restricts the completion of learning only according to the teacher's teaching plan. Secondly, in the cognitive process, modern educational technology teaching conforms to Gagne's cognitive learning theory, revealing the gradual development process of human mastering knowledge and forming potential: the traditional vocational and technical education and teaching process, especially the theoretical teaching part, is connected in series by perceiving teaching materials, understanding teaching materials and consolidating applied knowledge in turn, forming a long period of time, which makes students' memory easy to fade and is not conducive to the gradual development process. Modern educational technology integrates perception, understanding, consolidation and application, which strengthens students' memory in a short time and can effectively promote individuals to actively participate in the progressive learning process of continuous reorganization of cognitive structure. The so-called modern educational technology is based on modern educational ideas, theories and methods, guided by the viewpoint of system theory and based on modern information technology (at present, modern information technology mainly refers to computer technology, digital audio-visual technology, electronic communication technology, network technology, satellite broadcasting technology, remote communication technology, artificial intelligence technology, virtual reality simulation technology, multimedia technology and information superhighway). It is a comprehensive embodiment of modern teaching design, modern teaching media and modern media teaching methods. It aims to optimize the teaching process, teaching resources, teaching effect and teaching benefit.