Distributed architecture has been widely used in the design of reliable avionics. Distributed flight control computer designed based on Controller Area Network (CAN) is used for flight control law solution and system management of unmanned aerial vehicle (UAV). According to real-time UAV control and reliability needs, an inner communication mechanism of distributed flight control computer which integrates CAN communication, dual-port random access memory (DPRAM) communication and control tasks is put forward. Experimental results show that the communication mode designed according to the communication mechanism meets the real-time UAV control and reliability requirements, and solves the problem of the data delay caused by distributed architecture.