The simulation analysis is carried out for the main factors affecting the adjustment performance of the automatic adjustment device of the aircraft longitudinal control system. By analyzing the influence mechanism of the step size and loop width of the stair-like hysteresis error on the accuracy and reliability of arm regulation, the influence law of different matching resistances in the arm control circuit on the arm regulation performance is studied. The analysis results show that the step error width decreases with the increase of the common emitter resistance of the differential amplifier circuit, which reduces the accuracy of the system regulation, and at the same time, the working times of the force arm motor in the total stroke decreases; the return line voltage increases with the increase of the regulating resistance of the Schmidt trigger circuit, which affects the accuracy of force arm regulation; In the process of maintenance, attention must be paid to the change of the matching resistance of the control circuit, and timely adjustment should be made according to the needs to ensure the safety of aircraft longitudinal control.