The difficulty ranking of mechanical postgraduate schools is a complex problem, because different schools have different requirements for mechanical candidates, and each school's mechanical major also has different characteristics and advantages. Moreover, different candidates have different definitions of "difficulty". Therefore, the following rankings are for reference only, and the specific rankings need to be studied according to personal circumstances and needs.

I. Tsinghua University

Department of mechanical engineering, Tsinghua University is a key university directly under the Ministry of Education of department of mechanical engineering and one of the national key disciplines. The faculty of the department is strong, with many well-known professors and doctoral supervisors, and a large number of outstanding talents have been trained. Tsinghua University's mechanical specialty enjoys a high reputation at home and abroad and is recognized as one of the top mechanical colleges. So its postgraduate entrance examination is also one of the biggest difficulties.

Second, Shanghai Jiaotong University.

School of Mechanical and Power Engineering of Shanghai Jiaotong University is one of the well-known mechanical schools in China, with a long history and profound academic background.

The college has a high academic level and technical strength in the fields of mechanical design, mechanical manufacturing and power engineering, and has trained a large number of outstanding talents. The mechanical major of Shanghai Jiaotong University is also one of the popular majors favored by candidates, and it is difficult to take the postgraduate entrance examination.

Third, Harbin Institute of Technology

Harbin Institute of Technology is an engineering university with a long history, and department of mechanical engineering is one of its dominant disciplines. The department has high research level and academic influence in the fields of mechanical design, mechanical manufacturing and precision measurement, and has trained a large number of outstanding talents. The mechanical major of Harbin Institute of Technology is also one of the popular majors favored by candidates, and it is difficult to take the postgraduate entrance examination.

4. Huazhong University of Science and Technology

The School of Mechanical Science and Engineering of Huazhong University of Science and Technology is one of the well-known mechanical colleges in China, with strong scientific research strength and teaching level.

The college has a high academic level and technical strength in the fields of mechanical design, mechanical manufacturing and robotics, and has trained a large number of outstanding talents. The mechanical major of Huazhong University of Science and Technology is also one of the popular majors favored by candidates, and it is difficult to take the postgraduate entrance examination.

V Beijing University of Aeronautics and Astronautics

Department of mechanical engineering, Beihang University, is one of the well-known mechanical colleges in China, with strong scientific research strength and teaching level. The department has a high academic level and technical strength in the fields of aerospace, mechanical design and robotics.

A large number of outstanding talents have been trained. The mechanical major of Beihang University is also one of the popular majors favored by candidates, and it is difficult to take the postgraduate entrance examination.

To sum up, these schools are first-class institutions in the field of machinery in China, with strong teachers and excellent academic atmosphere, and have trained a large number of outstanding talents.

However, the postgraduate entrance examination in these schools is relatively difficult, which requires candidates to have a good academic background and a solid ability to take exams in order to successfully pass the exam. At the same time, different schools have different requirements for candidates, and candidates need to choose the school that suits them according to their actual situation.