The simulation modeling and control optimization simulation of the pitch control channel in the flight control autopilot of a certain type of civil aircraft were carried out. The model of the pitch control channel of the aircraft autopilot was modeled, and the model system of the channel was improved. The modeling of the control law of the pitch channel was completed in the development environment of Matlab, and the control optimization simulation of the system was completed in the development interface of Simulink, which involves the call of C language functions in Matlab, the construction of the automatic control system and the call of each module in Simulink. The PID controller and the ripple-free minimum beat digital controller were used to improve the system, the former improves the stability, accuracy and physical realizability of the system, and the latter optimizes the time parameters of the system to make it faster. The simulation results show that the adjusting time of the system is controlled within 1.1s, the overshoot is no more than 5%, the steady-state error is less than 1%, and the physical realizability, stability, accuracy and rapidity of the system can meet the basic requirements, the adopted method is direct and efficient, and the calculation precision of the model parameters can basically meet the requirements. Choosing Matlab/Simulink as the development tool is conducive to the construction of the control system model and the subsequent development of the modeling structure, which greatly reduces the difficulty of the development of the controller and the optimal simulation models for the system control, and provides powerful technical support and reference for the further development and application of the deeper self-test function of the more automatic driving instruments and system.