The main requirements for civilian UAV are small size, light weight, simple structure and high reliability. In this paper, we proposed a flight control hardware for civilian UAV based on STM32F103RE microcontroller. At first, the design of the overall scheme for the flight control system is introduced. Then, the main modules of this system are described in more details. A detailed block diagram is presented to show that all the modules are combined a into stable system. The results of flight experiment on miniature fixed wing show that this flight control system is feasible and reliable. The realization of the proposed system is so small that it can be packaged into a small box, which educed all the interfaces that are simple to mount on different carriers. Furthermore, this system has a refining, low cost, high reliability characteristics, so it is suited for mass production and use.