Anti-virus chip and anti-virus method

An anti-virus chip includes a first connection terminal, a second connection terminal, a detection unit and a processing unit. The first connection terminal and the second connection terminal are respectively coupled to a connection port and a system circuit of an electronic device. The detection unit detects whether the connection port is connected to an external device via the first connection terminal. When the detection unit detects that the connection port is connected to the external device, the processing unit performs a virus-scan program on the external device to determine whether a virus exists in the external device. When determining that a virus does not exist in the external device, the processing unit establishes a first transmission path between the first connection terminal and the second connection terminal. When determining that a virus exists in the external device, the processing unit does not establish the first transmission path.