With the popularity of new energy vehicles, the number of power batteries that need to be reused in cascade is also increasing. In the field of cascade battery reuse, how to achieve accurate, efficient and low-cost battery pack conversion is one of its central technologies. According to the characteristics of the cascade battery, after years of research on its sorting process, process and implementation tools, we developed a battery module based re sorting system.The system adopts modular design and energy replacement feedback design, which effectively solves the problem that single battery separation can not be realized in traditional battery module state, greatly reduces equipment investment and production energy consumption, and improves equipment utilization and production efficiency. The system is mainly composed of four parts: whole group charging and discharging, module single series charging and discharging, main controller, software and data