The invention discloses a charging device based on a power electronic transformer. The charging device includes a power electronic transformer, a control unit, a direct current meter, a bidirectional DC/DC converter, a DC/DC converter, a lithium battery energy storage unit, a low voltage auxiliary power unit and a control unit; the power electronic transformer is connected with the control unit, and a direct current bus is connected with the power electronic transformer; the direct current bus is also connected with a direct current charging gun; the direct current meter is also connected with the bidirectional DC/DC converter, and the lithium battery energy storage unit is connected with the bidirectional DC/DC converter; the direct current bus is also connected with the DC/DC converter; and the low voltage auxiliary power unit is connected with the DC/DC converter. The beneficial effects of the charging device provided by the invention are that alternating current charging and direct current charging can be output, control is flexible and convenient, and the charging device can be used for electric automobile charging, can reduce a large amount of construction cost of alternating current and direct current charging piles, and can reduce land occupation.