Heavy-ion beam radiation can cause cell DNA double-strand breaks (DSBs), which are factors that lead to genomic instability. Existing studies have demonstrated that homologous end joining, homologous recombination, single-strand annealing, and selective end joining play critical roles in the repair of DNA DSBs. However, the factors that affect the selection of repair pathways for DNA DSBs remain unclear. In this study, recent findings on DNA damage characteristics and repair pathways generated by heavy-ion radiation cells are reviewed, and the selection mechanism of DSB repair pathways in cells is explained in terms of the types and distribution of DNA DSBs, chromatin status, DNA terminal structures, DNA terminal excision, and cell cycles. This review is of great significance for the study of DNA damage repair and provides a reference for investigating the biological effects of heavy-ion radiation technology.