Abstract: How to eliminate or reduce the non-value-adding service process or process time of patient treatment for the radiology department is discussed. The Lean Value Stream Mapping (VSM) under the framework of the Lean Manufacturing system is a visualization tool used to describe the logistics and information flow, which has been widely used in the traditional manufacturing industries. Based on Lean Value Stream theories and simulation modeling methods, the service processes and process time of patient treatment in the radiology department of West China General Hospital are analyzed. By identifying the main bottleneck process, the constraints of the main bottleneck resource are further analyzed, a management problem of the physician team uniformly distributing patients′ diagnostic case information to write diagnostic reports is found out, and finally improvement programs and strategies of the main bottleneck process in the radiology department are proposed. The resource's rough-capacity matching mechanism of lean management is an effective way to improve patients treatment process of the radiology department.