Disclosed are a resistor, a heat dissipater and a combinatory device of the resistor and the heat dissipater, and relates to the field of power electronics. The resistor is cylindrical, and comprises a metal end, an insulating part, a casing, metal bars, a resistor wire, thermally conductive insulating fillers and a metal connection mechanism. The metal connection mechanism of the resistor and the heat dissipater are connected by means of direct contact. The structure and the connection method can shorten the length of the resistor, completely insulate the electrical circuits of the resistor from the possible leakage of the water inlet- and outlet-pipe of the heat dissipater, and enable the combinatory device of the resistor and the heat dissipater to be structurally more compact and the connections thereof cleaner.