A vehicle power conversion device includes: a housing configured to accommodate an electronic component therein and having an opening; and a cooling device. The cooling device includes a base being a plate-shaped member and heat sinks attached to the base. The base has a groove with refrigerant enclosed. The base has a first main surface to which the electronic component is to be attached, and covers the opening by the first main surface facing an interior of the housing. The heat sinks are joined, at intervals, onto the second main surface of the base.