Abstract: It can be inaccurate for reflecting the real operating conditions of the reactor core when applying simplified reactor core models to sub-channel simulations in traditional approach. The employment of high-performance computing technology has led to an increased amount attention on the simulation of refined full-core and real-channel-resolved. In this paper, an abstract description for the basic geometric structure of the fast reactor core was presented. Based on the abstract description, a full-core sub-channel modeling method and an adaptive parallel task division method were proposed. The breadth-first division algorithm and the hierarchical division algorithm were designed to realize the division of any number of solution domains of the full-core sub-channels. The division results adaptively mapped to different numbers of computing cores so that computing resources of different scales such as PCs, clusters and supercomputing machines could be used to carry out parallel simulations of the full-core. The sub-channel simulation software CTF, which was modified for fast reactor simulation, was used to verify the effectiveness of the modeling method for fast reactor subchannel simulation. Based on the test on the Sugon advanced computing service platform under two different grid-scale examples, the minimum parallel efficiency of the two test sets is over 33.02%, which proves the effectiveness and availability of the proposed method.