A stable DC power supply may be required in the high frequency pulse AC link inverter（HFPALI）.To meet this demand，this paper proposes a DC/DC converter that shares the high-frequency square-wave inverter with HFPALI after analyzing the characteristics of the HFPALI and LCL-T immittance network.Each working mode of this DC/DC converter is analyzed and the key waveforms are presented.The expression for the DC output voltage is then deduced.With respect to control，the grid-connected current of HFPALI can be adjusted with a cycloconverter and the DC output voltage can be controlled by shifting the phases of driving signals of the high-frequency inverter.So the grid-connected current control is independent of the DC voltage control.A simple phase shifting method is hereby proposed based on the digital signal processor（DSP）.Finally，the simulation and experimental results show that the proposed HFPALI system with DC/DC converter is stable in operation.