Aircraft flight control system is a typical complex system which includes control, electrical, hydraulic, mechanical and other fields. This paper introduces a set of multidomain modeling, simulation and code generation method based on Modelica for aircraft flight control system. Firstly, a multidomain flight control system model of a certain aircraft was implemented based on Modelica, which had been simulated and verified by experiment/flight test data. Then realtime code was generated from system model through the FMI technology, which was also engineering validation in the engineering development simulator. The method of modeling, simulation, code generation and semiphysical application proposed in this paper was suitable for the development process, which well met the designer’s habits and gave full play to the value of the model in the design process. Finally, the results of the simulation and the engineering development simulator test verified the effectiveness of the proposed method.