Abstract: This paper investigates arbitration algorithms of SpaceWire router, offers an dynamic weighted round-robin arbitration algorithm, the writer of this paper designs arbiter module according to the algorithm. It is based on priority and round-robin algorithms. The characteristics of the new algorithm is to avoid high-priority router ports will dominate the output port in the priority algorithm, and to resolve the problem that priority coefficients are excessively average. The new algorithm make router could admeasure priority coefficients according to the performance requirement of payloads, so the high real-time payloads can transmit data in time and reduce delay-time. The paper explains the design and implementation of arbiter module as the end.