The invention relates to the field of welding and cutting equipment, and especially relates to a three-phase staggered active PFC welding and cutting machine power supply. The three-phase staggered active PFC welding and cutting machine power supply comprises a three-phase staggered active PFC circuit unit for correcting a power factor and outputting stable high-voltage DC voltages and an inversion type welding and cutting machine power supply circuit unit for inversion, voltage reduction, rectification and filtering and outputting stable DC voltages and DC currents, wherein the three-phase staggered active PFC circuit unit and the inversion type welding and cutting machine power supply circuit unit are sequentially connected. According to the invention, the three-phase staggered active PFC circuit unit is employed as a pre-stage power supply of the inversion type welding and cutting machine power supply unit such that pollution caused by the inversion type welding and cutting machine power supply unit to a power network is isolated and shielded, and stable high-voltage DC power is also provided for the inversion type welding and cutting machine power supply unit portion. The three-phase staggered active PFC welding and cutting machine power supply has the advantages of small output ripples, small power device heating and low temperature rise.