The interface of data acquisition is an essential part of semi-physical simulation of UAV’s flight control system. In this paper, implementation of the interface of data acquisition is described in detail, S-Function and tlc are mainly introduced, and the application in the simulation of UAV flight control system is given. The practice shows this implementation can apply to flight control system successfully, reduce the difficulties in simulation, and have comparative advantages in some parts such as quality of simulation code, memory, and running speed.