A simplified control method for the series side of MMC_UPFC is realized by adopting indirect current control scheme for building simulation model more conveniently. Based on the MMC_UPFC system’s phasor model, the process for modeling and simulation of the simplified control strategy is deduced. Some simulation tests are built on the RTDS’s microsecond-level module based on one demonstration project of UPFC such as constant voltage phase shift control, active and reactive power flow control, and UPFC dynamic response under power grid disturbance, etc. Simulation results show that the simplified control strategy can make the MMC_UPFC system follow the control instruction fast and effectively and present regulation performance like good voltage control and phase shift and power flow control, etc.