本文以开源的APM飞控板的硬件原理、固件原理为基础，模块化搭建和研究飞行控制系统。文章对四旋翼无人机飞行控制系统的架构进行分析，硬件部分，采用模块化单元设计，替换更改部分元器件和接口，主要由32位的STM32F4处理器芯片，替换APM的Mega2560、Mega32u2的8位双处理器芯片，替换部分传感器，删除或添加了部分外部接口；软件部分，底层的驱动库源码程序，采用父子类的形式编写源码，实现源码的模块化，方便后期的软件升级和维护。该系统方案具实用性高、后期开发方便、经济性好等优点。 Based on the hardware principle and firmware principle of the open source APM flight control board, this paper constructs and studies the flight control system in a modular manner. The article analyzes the architecture of the quad-rotor UAV control system. The hardware part adopts modular unit design and replaces and changes some components. The 32-bit STM32F4 processor chip is mainly used to replace the 8-bit dual processing of APM’s Mega2560 and Mega32u2. The chip is replaced with some sensors, and some external interfaces have been deleted or added; the software part, the underlying driver library source code file, uses the parent-child class to write the source code, realizes the modularization of the source code, and facilitates later software upgrades and maintenance. The system scheme has the advantages of high reliability and high cost performance.