Intranet computer anti-violation external connection alarm

The utility model belongs to the technical field of relays, and particularly relates to an illegal external connection prevention alarm for an intranet computer. Comprising a box body, and a device socket is packaged in the box body; the other end of the device socket is sequentially connected with the single-chip microcomputer I/O port and the triode through lines, the other end of the triode is connected with the relay through a line, and the other end of the relay is connected with the second battery through a line; the relay is further connected with the sound-light alarm device through a circuit, the sound-light alarm device is connected with the first battery through a circuit, and a switch is arranged on the circuit. The computer USB port plugging device can play a role in physically plugging a computer USB port, and when the computer USB port plugging device is pulled out, a sound-light alarm is given out to remind an operator of being about to be connected with an intranet computer, so that informati