In order to realize the purpose of controlling the single chip computer through the upper computer of the PC,and controlling the slave computer through the single chip computer,a multi-machine communication system based on FreeRTOS for STM32F407 chip is designed.The system is based on FreeRTOS real-time operating system,with STM32F407 as the core,the PC upper computer sends information to the single chip computer host through Ethernet,and CAN command the single chip computer host to control the single chip computer slave through CAN bus,to achieve the purpose of multi-machine communication.This paper will analyze and design program software for CAN communication,Ethernet communication and other parts.The experiment results show that the design of the multi-machine communication system can successfully send information to the slave microcomputer and receive the information from the slave microcomputer,can realize the data transmission between multiple control modules,so as to achieve the mutual cooperation between the multi-computer to complete the target task.