The invention discloses a simulation system and method used for an automatic control system in the technical field of automatic control. The simulation system used for the automatic control system comprises the automatic control system, a data collection unit, a communication unit, a central processing unit, a data storage, a model establishment unit, a parameter setting unit, a simulation unit, a fault control unit, a simulation management unit, an assessment output unit, a program writing unit, a motion control unit and a patch board; according to the simulation system and method used for the automatic control system, the operation is convenient, the cost is low, through collecting data information of the automatic control system, a simulation model is built, the self-check of the simulation system can be conducted when the simulation is conducted, and the fault information is determined; through the artificial simulation management, the simulation results are output, the assessment is made, accordingly, bugs of the automatic control system are avoided, and cost waste and unnecessary risks are avoided.