According to the basic characteristics of arc welding and cutting, the multi-functional arc welding/cutting inverter based on phase shift-full bridge-zero voltage and zero current switches (PS-FB-ZVZCS) is designed. This paper analyzes design procedures and carefully selects components, which provide the theoretic foundation for the manufacture of PS-FB-ZVZCS inverter power sources. Then, this paper introduces the realization process of the output technique characteristics in arc welding/cutting, and also designs the controlling system. Through plentiful experiments and tests, it can be found that the shift of the arc welding/cutting power source is simple and the machine operates well in various working situations. As a result, it is thought to be suitable for arc welding/cutting applications due to its simplicity and robustness.