In order to realize various controls of different welding methods,a multifunctional digital inverter power supply is designed based on a central controller of Advanced RISC Machines（ARM）.Then,a digital human-computer interaction system based on ARM and Complex Programmable Logic Device（CPLD） is designed,which,combined with software design,implements the conversion and selection of such welding methods as CO2 gas metal arc welding,pulse MIG welding and manual metal arc welding.Finally,the processing properties of the designed multifunctional power supply are investigated according to the current and voltage signals acquired by a wavelet analyzer.The results indicate that the designed power supply with high practicability meets the requirements of diffe-rent welding processes and implements the multifunctionality of digital inverter power supply.