In the FAO train control system,an additional fault isolation function is provided between the platform screen doors and train doors in contraposition.Before the fault isolation function is implemented,the relevant functions need to be tested.The fault isolation function is achieved through the linked operation of multiple systems.The traditional test method involves the manual simulation of fault conditions,including the physical operation of the platform screen doors and train doors,and the manual simulation of the signaling systems,and has the problems of low efficiency and high costs.To meet the test requirements of improving efficiency and reducing costs,this paper presents the design of a simulation testing device for the fault isolation function.On the basis of a study of the indoor testing principles of the relevant functions,it proposes a scheme for the simulation testing device,and presents the achievement of the indoor testing function for the fault isolation function of the FAO signaling system.The proposed simulation testing device can effectively improve the product integration capability of the train control signaling system,and further ensure passenger safety and normal train operation.