An AV switching method capable of auto-configuring a plurality of AV input signals and associated apparatus is provided. An audio-video detector capable of auto-configuring the AV input signals includes an audio-video detecting module, an impedance adjustment module, and an audio-video switching module. The audio-video detecting module receives and detects the AV input signals to generate an AV detecting result. The impedance adjustment module adjusts matching impedance for the AV input signals according to the AV detecting result. The audio-video switching module switches the AV input signals to output AV output signals according to the AV detecting result.