Abstract: To investigate the control mechanism of plasma actuation on the boundary layer separation and the total pressure loss of the low-pressure turbine cascade with incoming wakes, a numerical simulation is conducted to analyze the effect of plasma actuation on the flow field. The influence of the actuation position on flow control effectiveness is explored in detail. As the actuation position moves from upstream of the time-averaged separation point to the trailing edge, the total pressure loss coefficient at the outlet exhibited a trend of initially decreasing and then increasing. When the actuator is located 5% axial chord length downstream of the time-averaged separation point, the boundary layer separation at the rear part of the suction surface is completely suppressed, and the total pressure loss coefficient at the outlet decreases by approximately 10%. Plasma actuation applied at the rear of the suction surface can effectively suppress boundary layer separation on the suction surface while having little effect on the flow field in the end wall area.