Disclosed in the present invention is a four-port power electronic transformer based on a hybrid modular multilevel converter (MMCs). The four-port power electronic transformer includes a hybrid MMC, direct current (DC)/DC converters, and an inverter. Each DC/DC converter includes a front stage part, a high frequency transformation part and a back stage part. Compared with an existing power electronic transformer, the present invention has the following characteristics: an MMC module and a front stage of a DC/DC circuit connected to the MMC module jointly complete DC fault ride-through, and the number of adopted devices is small; the MMC module controls a DC voltage and the DC/DC circuit controls power; voltages of one or two capacitors in the module can be controlled independently or simultaneously; and the four-port power electronic transformer has four ports: a high-voltage DC port, a high-voltage alternating current (AC) port, a low-voltage DC port, and a low-voltage AC port, and is applicable to a high-voltage high-power scenario with multiple voltage types and levels, particularly to the energy internet to be used as an energy router and the like.