Based on the concept of contention reservation, polling transmission and combining distributed clustering network architecture, an user-dependent perfect-scheduling multiple access (UPMA) protocol for supporting node mobility and multihop architecture in wireless self-organizing networks was described, and its performance of intercluster communication was simulated by OPNET. By clustering algorithms, two-hop cluster architecture for polling mechanism was formed to support multihop network topology. The protocol includes reservation access phase and polling phase in channel period. In the protocol, the nodes with packets to send contend to reserve channel resources during access slots of every frame. If successful, they were polled to transmit their packets in subsequent frames. If not, collision avoidance and resolution process was used for efficient access. The simulation results show that the proposed protocol can greatly improve multihop transmission efficiency, and achieve higher end-to-end channel utilization, lower average end-to-end message delay and less average message dropping rate.