Topology mismatching between the overlay network and physical network is a main factor which affects the routing performance of structured P2P network. A detecting and decreasing links overlapped scheme(DDL) is proposed. It examines the overlapped physical links caused by overlay routing, and on the appropriate condition, sends the redirect messages to decrease the physical links crossed. DDL solves the topology mismatching problem on the physical network level, and it can be used in any structured P2P network without the limitation of overlay structures. According to different definitions of links overlapped, backward and forward DDL schemes are described in detail. Through performance analysis and simulation, DDL scheme can dramatically improve the topology consistency.