Abstract: Embodiments of the present application provide an insulation and heat radiation structure of a power device, a circuit board, and a power supply apparatus. The insulation and heat radiation structure of the power device includes a power device, an insulation ceramic piece, and a heat radiator, where the power device is of a sheet structure, the insulation ceramic piece is an alumina ceramic piece, a heat radiator pin is disposed on the heat radiator, the heat radiator pin is used for being mechanically connected to the circuit board, a heating surface of the power device is adhesively fixed to one surface of the insulation ceramic piece through a first insulating thermal conductive adhesive, and the other surface of the insulation ceramic piece is adhesively fixed to a contact heat radiation surface of the heat radiator through a second insulating thermal conductive adhesive.