Composite heat-conducting PCB

The invention belongs to the technical field of PCBs, and particularly relates to a composite heat conduction PCB. The circuit board comprises a substrate, a heat dissipation layer and a shell; the shell is fixedly connected to the lower portion of the substrate, heat dissipation holes are formed in the shell, the heat dissipation layer is fixedly connected with the inner wall of the shell, a sliding heat conduction module is arranged above the heat dissipation layer, and the sliding heat conduction module comprises a first electric push rod, a second electric push rod, a first sliding heat conduction base, a second sliding heat conduction base and a controller; the controller on the back face of the substrate induces heat to control the sliding heat conduction module to move to a high-temperature position, and heat on the high-power component is directly transmitted to the heat dissipation layer through the sliding heat conduction module; and the heat on the heat dissipation layer is discharged through the h