Abstract: In recent years, with the continuous development of high performance computing technology, relying on advanced supercomputers and mathematical physics calculation methods, multi-physical and multi-scale calculation of nuclear reactor become a hot research topic. According to the requirements of multi-physical coupling analysis of reactor core, the multi-physical coupling algorithm was studied, the multi-physical coupling system of reactor core based on neutron transport, burnup and thermal sub-channel was constructed, and the coupling program was developed. Multi-physical coupling calculation of neutron physics, burnup and thermal sub-channels was realized. The pressurized water reactor module model and the fast reactor model were used to carry out the transport-burnup coupling calculation test and the nuclear-thermal coupling calculation test, and the coupling system function is preliminarily verified.