Abstract: A digital pulsed CO₂ welding power supply with sloping output characteristics based on digital signal pro-cessing controller was developed.It can automatically regulate the slope of external characteristic curves with predominant slop-ing characteristic algorithm in the welding process,and imple-ment the stability of welding arc in wide field.In this system,the average arc voltage is preset in accordance with the feeding rate of a separate wire feeder,while full-bridge inverted main circuitry can be adopted independently.The digital pulse width modulation signals are generated directly at low hardware ex-pense,and the control strategy is implemented through software.Furthermore,the needed slope rate of output characteristics is calculated with the software,the control signal is created and converted to dual-edge pulse output signal,and the arc voltage is automatically adjusted to maintain a stable arc.The simplified configuration shows high reliability,and the control program can also be updated by means of the upgrade interface for property enhancement.Welding test showed that the pulsed power supply with the sloping output characteristics has high stability and reli-ability.