Aiming at a mechanical transmission,the simulation and modeling of the transmission is carried out based on Romax software,the relationship between transmission efficiency and gears,oil temperature,torque is obtained through simulating the real operating condition of transmission. Meanwhile,according to the transmission structure and test requirements,a test bench is designed,and the correlation test of the transmission is carried out and the results are collected. Under the same condition,the simulation results are consistent with the test data from the test bench and the correlation coefficient between these two is 0. 937 4,which shows a high-positive correlation. The transmission model established by Romax software can be reasonable and effective in place of test data,which provides theoretical foundation for the design and optimization of mechanical transmission.