Abstract: Data mapping is a widely used data mapping method in peer data management systems.It can improve the degree of the data share by creating a new kind of mapping skillfully.Based on a series of research，this discourse advances a data mapping inference algorism of either peer in complex path，in the process of mapping inference，makes sure of the optimum route according to optimization principle and then linear path data mapping inference to ascertain the connection of the mapping of the peer-to-peer，thereby resolves the data mapping inference of either peer in complex path.