The AODV routing protocol, which is simple and efficient, is often used in wireless sensor networks to transmit data. The AODV routing protocol constructs a path from the source node, which detects the target, to the sink node. Whenever the target moves, the path will be reconstructed and the RREQ packet will be broadcasted to flood the wireless sensor network. The localization repair routing protocol sets up a reconstruction area and restricts the broadcast of the RREQ packet to that area to avoid broadcast storm. However, this method cannot reconstruct the path once the target moves out of the reconstruction area. In this paper, we propose a lightweight routing protocol for mobile target detection. When the path breaks because of the movement of the target, the nodes can repair the path effectively using the presented routing information to achieve the lightweight effect.