Abstract: Elaborated in the paper is the structures and applications of both the hardware and software systems of a multi-parameter synchronous detection system for the arc welding process. As a virtual instrumental system based on computer data acquisition system and composed of relevant software,this system has not only the basic interfacial effect and convenient operating functions similar to those of the conventional instrument,but also powerful mass data recording ability,easy data playback function,and various functions for welding parameter analysis,being capable of quantitatively analyzing of quality stability of the arc welding process. Since this system is especially designed for the arc welding process,it can be directly used for the arc welded pipe production line. Moreover,it can also be further applied to the HFW pipe or seamless pipe manufacturing process just after having its operation interface and data display formats appropriately amended.