The utility model relates to an optic silicon crystal high-definition digital TV set with the function of set-top box, a set-top box circuit is arranged in the case, the video signal output end of the set-top box is connected with the video signal input end of the image processing chip of TV set core circuit. An intelligent on-off relay circuit for AC power source time-delay cutoff is also designed to solve the problem of the heat dissipation of the silicone-based LCD of the optic silicon crystal high-definition digital TV set. People can watch digital TV programs only by using a remote controller, and the disorderly connection wires between set-top box and TV casing are omitted so that indoor layout is more beautiful. Aiming at the problem of the heat dissipation of the optic silicon crystal high-definition digital TV set, the optic silicon crystal high-definition digital TV set realizes automatic time-delay cutoff of AC power source after shutdown.