A video signal communication method, applicable to IP phone, the method comprises of the following steps: when starting up the supporting video signal function, also starting to receive transmission using video related communication protocol; receiving the internet address setting of the video processing device to retrieve the internet address of the video processing device; determining if the video processing device is initialized; determining if the connected video processing device is initialized and then transmitting the received video signal to the video signal processing device; processing video signal via the compression/decompression module, and the video processing device displaying the video signal.