Flight control and management system software of unmanned aerial vehicle (UAV) is developed according to specific application scenarios and requirements, which lead to poor software adaptability and portability, restricted the efficiency of software migration, and increased the development cost and cycle of UAV system. In order to meet the design principle of “reliable work and flexible expansion” of UAV flight control and management system, a general software architecture for distributed and redundant flight control and management system was proposed by studying the integrated modular avionics (IMA) system, airborne software architectures and airborne operating systems, combined with the requirements of UAV flight control and management system. Based on the study of UAV functional requirements, software security and demand for collaborative development, the software function partition was designed by adopting the open and hierarchical design concept, and the standardized interfaces of system calls and run-time library were made clear, which given full play to the advantages of IMA system, adapted to the existing UAV flight control and management system, realized software reuse to the maximum extent, and reduced the cost of UAV airborne system development.