The invention discloses a signal detection device of a VGA channel, and the signal detection device comprises a television MCU, a VGA terminal for connecting an external VGA signal source and receiving VGA signals, a VGA line synchronous signal processing circuit for converting VGA line synchronous signals to VGA detection signals, and a VGA field synchronous signal processing circuit for converting VGA field synchronous signals to the VGA detection signals, wherein the television MCU is used for receiving the VGA detection signals and judging whether the VGA channel has the VGA signals or not. The signal detection device of the VGA channel has the advantages of simple structure and low cost, and the signal detection device can stably and reliably detect the signal state of the VGA channelof a television and can be applied to a variety of VGA terminal-based application occasions.