The invention discloses a prefabricated cabin substation having the phase change temperature regulation function and a temperature control method thereof. The prefabricated cabin substation comprisesa prefabricated cabin, wherein the prefabricated cabin is provided with a phase change heat accumulator, a side wall of the prefabricated cabin facing the sun is provided with a heat radiation ventilation assembly, the heat radiation ventilation assembly comprises an air channel and a heat collection plate, the front surface of the air channel is a transparent plate, an upper portion of the air channel is provided with an air outlet and a first ventilation port, a lower portion of the air channel is provided with an air inlet and a second ventilation port, the first ventilation port and the second ventilation port are respectively communicated with the prefabricated cabin, the prefabricated cabin is further provided with an auxiliary air port, the air outlet, the air inlet, the first ventilation port, the second ventilation port and the auxiliary air port are respectively provided with an electrical air valve, the heat collection plate is arranged in the air channel, and the prefabricated cabin is provided with a temperature controller linked with the multiple electrical air valves. The prefabricated cabin substation is advantaged in that mounting cost and operation energy consumption of the prefabricated cabin substation are reduced, and heat radiation performance is improved.