In view of the lack of research on dynamic route optimization for responsive feeder transit(RFT) system, a dynamic route optimization method based on key points under dynamic demand and dynamic travel time was proposed.Taking passenger demand points and nodes in road network as key points,the dynamic route update rules and update processes based on key points were proposed. A route optimization model at key points was constructed to minimize total operation cost for RFT with simultaneous pick-up and delivery, single type multi vehicle. At the same time, a genetic algorithm was designed to solve the model. The results show that the suggested method can effectively obtain the dynamic optimal route of RFT under dynamic demand and dynamic travel time.Under the same passenger demand and in the same road network, the composition mode of key points including demand points and road network nodes can better adapt to dynamic road network, also help to save travel cost.The operation mode with simultaneous pick-up and delivery can prominently reduce the number of departure and total travel time, and improve average seat utilization. Key point composition and operation mode have significant influence on dynamic optimal route and operation efficiency.