Abstract: Digital current sharing technology was used to increase the cutting current of the whole system to improve cutting ability and carry out the thick plate plasma cutting.A high-power plasma cutting power supply system was designed,and the plasma cutting power supply control system was built based on the digital processing chip STM32F405RGT6.The full digitalized control of plasma cutting power supply was realized.The digital average current algorithm was used to realize the parallel current control of the power supply in parallel,which ensured the stable and uniform current of the single power supply.Experimental results of current mean flow tests and thick plate plasma cutting tests indicated that the design of plasma cutting power supply parallel cutting power works stably,current distribution is equably,and the cutting quality is good.