In this work, the permanent magnet frequency conversion tensioning system of belt conveyor is designed. The permanent magnet synchronous motor and belt conveyor are modeled and simulated in AMESim and MATLAB co-simulation environment. The dynamic characteristic curves of impact load of belt conveyor in different running stages are analyzed. In addition, the experimental platform of permanent magnet variable frequency tensioning system is built, and the change of tension in different stages is analyzed experimentally. The results show that compared with the traditional hydraulic automatic tensioning system, the permanent magnet variable frequency tensioning system has faster response speed, higher safety and reliability, and better dynamic characteristics.