In order to explore a promotable and effective train-the-trainer program conducted by core simulation faculty within the hospital, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine has organized and implemented an in-hospital train-the-trainer program for simulation faculty based on experiential learning since 2022. This study introduces the design and implementation of the train-the-trainer program and investigates its effectiveness. All 26 trainees have participated in teaching practice, four teaching teams formed, and 23(88.5%) of the 26 trainees have served as debriefers once or more. The results of the questionnaire showed that out of 26 trainees, 26(100.0%) trainees believed the training could improve their knowledge structure for scenario-based simulation, 25(96.2%) trainees believed that the training can stimulate them to actively explore relevant knowledge in scenario-based simulation, 25(96.2%) trainees recognized the training method at each stage, 26(100.0%) trainees believed that the training will be helpful for their future teaching practice. Focus group interviews were conducted with trainees, and the results showed that the design and implementation of such programs need to follow the learning cycle, and transforming teaching thinking patterns is the fundamental factor for novice simulation faculty to master the teaching method of scenario-based simulation. It can be seen that train-the-trainer program that conforms to the experiential learning theory helps novice teachers master the teaching method of scenario-based simulation, and achieving self-reflection and transformation of their own teaching thinking patterns. This study can inform medical institutions in China to play the role of core simulation faculty and carry out effective train-the-trainer program for simulation faculty.