Provided is a simulation device of a satellite, which updates a set value of a simulator, using a command signal transmitted to the satellite, operational data received from the satellite, and flight information. The simulation device of the satellite may comprise: a communication unit for receiving operational data from the satellite, and transmitting a command signal to the satellite; a flight control unit for calculating flight information of the satellite, using the received operational data; and an updating unit for updating a set value used for simulating an operation of the satellite, using at least one of the operational data, the command signal, and the flight information.