Abstract: The traffic and topology adaptive routing algorithm conbined with topology structure and operating rules is proposed in this paper, which can increase the throughput of the system. Also, due to the dynamic topology of LEO system, the connection may be interrupted because of handover failure. In order to minimize the handover failure probability, dynamic channel reservation strategies are also taken into account at the same time. The simulation results show that the system performance can be improved as a result of dynamic channel reservation for handover calls.