Abstract: When the link line between lines is shorter due to civil engineering, in condition of axle counter disturbed at link line boundary, operation of the main line can be affected. An optimized design scheme is proposed: an additional axle counter point is arranged on the link line, and a section without switch is separated, the occupied and idle information of which is shared by the signaling systems of two lines. The design scheme has avoided limit invasion, as well as the situation of disturbance of axle counter point at link line boundary affecting operation of the main line. Time of fault emergency repair can be reduced, lowering influence on operation. Availability of the signaling system and operation efficiency are improved. The proposed design method has been applied to the link line of Zhengzhou Metro Line 4.