Abstract: In this paper,space-vector PWM (SVPWM) control method is introduced in the power factor correction (PFC) of arc welding inverter source.The input voltage vector of PWM rectifier is regulated to control the input current by changing manipulative time of eight basic vectors.The principle of SVPWM control is presented in detail and the implementing way is also discussed.According to the characteristics of arc welding inverter source,simulation results based on Saber software show that the proposed control method is a practical way to carry out the PFC of arc welding inverter source.Experiments exhibit that the inverter based on DSP controller source has low current distortion,high power factor and good transient response of the input current in AC side.The proposed method gives a new choice to meets the demand of PFC of arc welding inverter source.