A power supply device having function of heating includes a body, a circuit board, and a heating plate. An accommodation space is defined in the body. The circuit board is disposed in the accommodation space. An input connector and an output connector are disposed on the circuit board. The circuit board receives an external power via the input connector, selectively transforms the external power into a first output power or a second output power, and outputs the first output power via the output connector. The heating plate is disposed on a bottom side of the body and electrically connected to the circuit board to receive the second output power to generate heat for increasing the temperature thereof. The thermal insulator is disposed between the circuit board and the heating plate for isolating heat transferred from the heating plate to the circuit board.