A keyboard scanning circuit, comprising N wires, and [(2N−1)+(2N−1−1)N] switches divided into two switch groups, therein N is a natural number. Each switch includes a first contact and a second contact. The first contacts of the (2N−1) switches in the first switch group are connected to ground, the second contacts of the (2N−1) switches in the first switch group are connected to the wires in (2N−1) connectors. The first contacts of the (2N−1−1)N switches in the second switch group are connected to one of the wires, the second contacts of the (2N−1−1)N switches in the second switch group are connected to the nodes between the switch in the first switch group and the wires.