The invention discloses a heat dissipation capacitor which comprises a body, a top cover and an inner cavity. A metal layer is fixedly arranged outside the body; the metal layer is in sealing connection with the body; a water accommodating cavity is formed between the metal layer and the body; a heat conduction resistance separator is arranged in the water accommodating cavity; the heat conduction resistance separator separates the water accommodating cavity into an inner layer cavity and an outer layer cavity; the heat conduction resistance separator is fixed on the body by a joint pin; both the upper ends and the lower ends of the inner layer cavity and the outer layer cavity are communicated; moreover, a plurality of heat dissipation grooves are uniformly distributed on the periphery of the metal layer. The heat dissipation capacitor has a simple structure; by arranging the heat conduction resistance separator between the body and the metal layer, self-circulation of cooling water can be realized between the inner layer cavity and the outer layer cavity so as to effectively carry out heat dissipation; the heat dissipation capacitor does not need to be driven by an external power, so that cost resources are greatly saved; meanwhile, the formed heat dissipation grooves improve a cooling rate of the metal layer, so that a heat dissipation rate is further improved.