A power conversion apparatus is provided, which comprises a housing, a mother board, an electromagnetic filter board, a signal board, and a heat-dissipation module. The housing includes a first heat-dissipation wall and a coolant passage. The mother board is disposed upon the housing, and comprises a first surface facing the housing and a first power device. The heat-dissipation module includes a first insulated heat-conducting sheet adhered to the corresponding first heat-dissipation wall and a first elastic clamp. When the first surface of the mother board approaches the housing to clamp the first power device within the accommodating space, the first power device is pressed against by the first elastic clamp and thus adhered to the first insulated heat-conducting sheet, so that the first power device is thermally coupled to the first heat-dissipation wall and the coolant passage via the first insulated heat-conducting sheet.