Abstract: The pulsed switching power supply was developed for deep tumor therapy facility with heavy ions in coolerstoragering of the heavy ions research facility in Lanzhou (HIRFLCSR). The control principle of the dual closedloop scheme was described and the openloop Bode diagrams were given. The results of simulation and prototype experiment show that the current error gets much smaller than that of the single closedloop pulsed switching power supply. Moreover, the simulation and test results were analyzed, and the circuit configuration and dual closedloop strategy selected are practicable.