The invention discloses a composite heat conduction PCB, and relates to the technical field of PCBs. The technical scheme is that the composite heat conduction PCB comprises a heat exchange assembly, a heat dissipation assembly and an electric shielding assembly, the top of the heat exchange assembly is fixedly provided with the heat dissipation assembly, and the top of the heat dissipation assembly is fixedly connected with the electric shielding assembly; the heat exchange assembly comprises a heat exchange seat, a lower heat dissipation sheet and an upper heat dissipation sheet, connecting frames are evenly installed on the inner wall of the heat exchange base, and heat dissipation holes are evenly formed in the outer wall of the periphery of the heat exchange base; the lower heat dissipation fins are fixedly connected with the upper heat dissipation fins in a matched manner, the heat dissipation assembly comprises a strengthening net, heat dissipation silicone grease and a circuit board substrate, and the circuit board substrate comprises a first circuit board, a second circuit board and a third circuit board. Through the cooperative use of the upper cooling fins and the lower cooling fins, the heat of the circuit board above can be conveniently transferred, so that the heat dissipation efficiency is improved; and air is in contact with the rectangular fins under the action of the heat dissipation holes, so that the heat dissipation efficiency is improved.