A control method for a TV system is provided. The TV system has a digital signal port connected to a player. The control method includes the following steps. After the TV system is turned on, a first set value is written into an EDID rewritable memory of the TV system. After the player is connected to the TV system, the TV system judges whether a quality of the first digital signal group is good or bad. If the quality of the first digital signal group is good, a video/audio signal is issued by the TV system according to the first digital signal group. Whereas, if the quality of the first digital signal group is bad, a second set value is written into the EDID rewritable memory.