Abstract: A turbofan engine and its main fuel control system with hydromechanical regulator are studied.The rotational speed control system and the acceleration control system are modelled according to the analysis of the engine control program.The temperature sensor,temperature amplifier and blade control system are also modeled.According to thse mathematical models,all systems are simulated with the SIMULINK in toolbox of MATLAB.This work has important value for further research and improvement in the engine main fuel control system.