In order to improve the efficiency and quality of medical services,the authors applied the lean production and system simulation into optimizing the transfusion system of a hospital.By means of describing and analyzing the current situation and problems of a transfusion system of the hospital,the paper presented the cause-effect diagram for overlong patient waiting.5W1H and ECRS were adopted to analyze the infusion processes,while Simio was used to simulate the existing infusion system and simulation data so obtained were used to draw a value stream mapping for the system.In line with the ideas of Shojinka and one stream production,nurses deployment and conveyor speed were reconfigured.Based on these ideas,a reform plan is presented and the simulation method is used to verify the outcomes.The study proved that lean production and system simulation can effectively improve the hospital transfusion system,medical efficiency and medical service level.