The DC power output tracking command current of the electric welding machine has some problems such as static error and poor anti-interference ability when three-phase PWM rectifier is controlled by traditional proportionalintegral（PI）. For these problems,the quasi-PR of inner ele-ctric current loop is adopted,the PI of outer input current loop and outer voltage loop is adjusted,and the double closed loop control strategy of output voltage is also adjusted,the shortcomings of traditional linear PI control are overcome. In this paper,the mathematical model of the system is established,and the principle of SVPWM generator and quasi-PR controller is analyzed. The simulation results show that the SVPWM control strategy of DC electric welding machine based on quasi-PR can realize the complete non-static tracking of electric welding machine DC power unit power factor and current,and the electric welding machine power has good anti-interference ability and excellent rectification quality.