The invention discloses a power electronic transformer based on simple PFC (Power Factor Correction). All single phase structures in a three-phase circuit are same and independent to each other, wherein each phase comprises an input grade, an isolation grade and an output grade; input ends of an input-grade power transformer group and an output-grade power transformer group of each single phase are connected in a star shape; the input grade of each single phase adopts a series connection way; the input-grade power transformer group comprises a diode bridge-type circuit and a buck circuit and can realize the control of a power factor, and the alternating side of each power transformer group is connected in parallel with a pressure sensitive resistor; the isolation grade comprises a high-frequency DC / AC, a high-frequency transformer and a high-frequency AC / DC link, wherein a primary edge of the high-frequency transformer is connected in series with a capacitor, and the loss consumption of a switch tube is reduced under the action of a resonance soft switch; an output side of the isolation grade adopts a parallel connection way; and the output-grade power transformer group adopts a bridge-type inverting circuit, and an output side of the output-grade power transformer group is also connected with a filter. The invention has the advantages of simplifying the circuit structure, reducing the cost, realizing the power factor correction and resonance soft switch and increasing the conversion efficiency.