The present utility model provides an electronic device and a power module thereof. The power module of the present utility model includes: a first circuit board, a second circuit board, a radiator and a power device; where the heat dissipation surface of the power device is in thermal contact with the radiator, and the heat dissipation surface of the power device is parallel to the first surface of the first circuit board. The present utility model improves the heat dissipation efficiency of the power device by mounting the power device on the second circuit board and thermally contacting the radiating surface of the power device with the radiator, and at the same time, the arrangement of the second circuit board also makes the assembly of the entire power module more convenient.