Abstract: For the pulsed waveform modulation of GMAW-P (gas metal arc welding-pulsed arc), a novel DSP based digital control system for GMAW-P was presented, which was established based on 16-bit fixed point digital signal processor (DSP) TMS320LF2407A.By adopting the PWM generation modules integrated in DSP and selecting their reasonable working mode, the digital control of PWM signal was realized, so the high frequency inverter and low frequency pulsed waveform modulation of GMAW-P were realized, and the stability and reliability of control sy stem were improved. The design of software to the control system was also discussed. Experimental results show that the developed digital control system has the ability to accomplish the excellent welding process and appearance of the weld is good, the merit of DSP based digital control system is fully demonstrated.