This paper introduces the main structure of 500kVar/10kV static synchronous series compensator model machine. Based on PSCAD/EMTDC，the electromagnetic simulation model is proposed. Taking practical environment of the model machine as background, it approves the rationality of parameter design for equipments such as low-pass filter, coupling transformer, direct capacitor and so on. The transient phenomenon during operational pattern switch is analyzed. The capability of direct voltage regulation and dummy bus voltage regulation is validated in this paper. These studies provide theories for the development of model machine.