A control method for integrating a display device with a digital television (DTV) module, which includes the steps: (A) using the display device to execute a system program; (B) determining whether the display device is in a digital television mode; (C) further determining whether the display device receives an instruction when step (B) decides that the display device is in the digital television mode; (D) further determining whether the instruction received is for the digital television module when step (C) decides that the display device receives the instruction; and (E) using the display device to send the instruction to the digital television module through a serial bus and to receive and process a response of the digital television module when step (D) decides that the instruction is for the digital television module.