HDMI cascaded LED sending card device

The utility model relates to an HDMI (High-Definition Multimedia Interface) cascaded LED (Light Emitting Diode) sending card device, which comprises at least one LED sending card, and the LED sending card is provided with an HDMI output interface and an HDMI input interface which are used for transmitting a video signal and a communication signal between the LED sending cards. The HDMI output interface and the HDMI input interface realize transmission of a video signal and a communication signal by redefining two unnecessary pins in the HDMI interface, the HDMI output interface of the LED sending card is electrically connected with the HDMI input interface of the next level of LED sending card, and the HDMI input interface of the LED sending card is electrically connected with an upper computer. According to the invention, two unnecessary pins of the HDMI interface are redefined, so that the HDMI interface has the function of transmitting video signals and communication signals, and a video interface and a co