The cooling function power adapter inserts between the ionization gauge tube prongs and the power socket. Its unique cooling function dissipates the heat generated by the ionization gauge tube working under large power current. This adapter also lowers the working temperature of the power socket. This invention prevents or minimizes the condition where the materials of the power socket carbonize, discolor and/or deteriorate. Additionally, this adopter is designed with easy plug-in and non-directional feature, maintenance and replacement of the adapter take only seconds. This adapter ensures that the power socket is able to working under long periods of time under large power transmission. The fan cooling function further minimizes safety hazards.