The China Spallation Neutron Source (CSNS) Rapid Cycling Synchrotron (RCS) is a high beam power proton accelerator.The task of RCS injection system is to inject the negative hydrogen ions coming from linac into RCS by stripping method.This power supply demands that its output pulse current falling edge be controlled by the program. The power supply uses the IGBT power amplifying method to generate the pulse current and makes it follow the setting waveform by the power supply's feedback control system.The tracking error is one of the important specifications of the power supply.To satisfy the tracking error less than 2%,the frequency of the IGBT topology requested is more than 400kHz.The IGBT topology is connected by the IGBT H bridges in series and parallel,and works in the phase shifted method to divide the current,the voltage and improve the equivalent frequency.High power,high frequency,fast speed response and optimal feedback control strategy are the key to the good performance of painting bumper magnets pulsed power supply.