The utility model provides a novel three -phase variable frequency power supply, relates to a power. At present, adopt three -phase regulator output conduct power when testing usually, the huge heaviness of equipment size, it is troublesome to use, easily influences the electric wire netting, the utility model discloses a single phase power input module, AC DC conversion module, frequency conversion module, transformer boost module, three -phase electricity output module, frequency conversion module include SPWM inverter circuit, signal generating unit, SPWM ripples generation unit, feedback control unit, display element, the control unit, protected location, input unit, the control unit and display element, signal generating unit, input unit, protection identity element, SPWM ripples generation unit, feedback the control unit link to each other. This technical scheme is at each item performance index who reduces under the power supply size weight to optimize output voltage by a wide margin, overcomes each item drawback of traditional voltage regulator, experimental reliability and the accuracy requirement of fully provided.