A power conversion module for a vehicle is provided. The module includes a housing and a power conversion unit installed on an inside surface of a bottom panel of the housing. The power conversion unit includes a capacitor module, a power module of an inverter and a LDC. A water-cooling-type cooling unit is installed on an outside surface of the bottom panel of the housing and is in a corresponding position to the power module of the inverter and the LDC, with the bottom panel of the housing interposed therebetween. An air-cooling-type cooling fin is installed on the exterior surface of the bottom panel and is in a corresponding position to a capacitor module, with the bottom panel of the housing interposed therebetween. A radiator blower adjacent to a radiator of a vehicle is configured to generate cooling-air wind to cool the radiator and the air-cooling-type cooling fin.