Abstract: In order to improve the dynamic response performance of the arc welding inverter power system,the inductance L of the inverter power transformer was optimized,and two methods for improving its dynamic response performance were proposed. That is,under the premise of ensuring that the ratio of the simplest turns of the primary and secondary sides of the transformer was unchanged,the number of turns of the primary and secondary sides of the transformer was reduced or the input and output ends of the transformer were connected in parallel to improve the dynamic response performance of the arc welding inverter. Simulink simulation software was used to build the main circuit model and control system model of the arc welding inverter power supply,which proved that the transformer inductance L had an impact on the dynamic performance of the closed-loop control when the load changed instantaneously. The PSpice simulation software was employed to build the main circuit model of the arc welding inverter power supply and the transformer model to prove the feasibility of the two methods.