Abstract: The application of power electronic technique in welding domain resulted in miniaturization and high electronic efficiency of welding inverter,and at the same time,its rapid dynamic response made it a good platform for any arc process control.But as the development of technology,the shortcomings of traditional analogue control circuit have become the bottleneck of further promotion of welding technics.This paper introduced the digitalization of welding inverter and its future development on the basis of illumination of the DSP's basic characteristics.A part of research on this subject of Beijing Polytechnic University was also addressed.