The process of system debug and the experiment results of microprocessor controlled multi-function inverter power source are introduced in the paper. The protection of the system and the optimized measures of PI control, parameters display subroutine are respectively analyzed. 介绍了单片机控制多功能逆变焊机系统调试过程及试验结果,分析了系统保护、PI控制和参数显示控制软件的优化方法。