Power supply input protection circuit, HDMI receiving device and television complete machine

The utility model discloses a power supply input protection circuit, which is respectively and electrically connected with a receiving interface and a main board on HDMI (High Definition Multimedia Interface) receiving equipment, and comprises a switch module which is respectively and electrically connected with the receiving interface and the main board and is used for receiving input voltage output by HDMI sending equipment and controlling the connection and disconnection between the receiving interface and the main board; and the overvoltage protection module is electrically connected with the switch module and the receiving interface, and is used for receiving the input voltage, comparing the input voltage with a preset voltage threshold value, and outputting a control signal according to a comparison result to control the on-off of the switch module. Through the arrangement, when a user misconnects the HDMI sending equipment with other power adapters, and if the overvoltage protection module monitors tha