A cooperative networking scheme and corresponding network protocol model based on relay is proposed after the analysis and comparison towards the existing integration schemes.A new networks protocol layer called universal cooperative adapter layer is added above MAC layer in relay node for the data transformation and cooperative transmission under heterogeneous network environment.And the cooperative radio resource management entity is introduced into base station and relay for cooperative networking of multiple relays and negotiation of transmission capacity and quality among different radio access networks.The experiment results revealed that the proposed scheme could achieve the integration of multiple radio access technologies effectively and provide high rate transmission services accompanied with the cooperative employment of multiple wireless access networks resource.