In order to break through the flow pulsation problem of traditional electro-hydraulic servo system, an active flow distribution electromagnetic direct drive hydrostatic actuator based on active check valve and electromagnetic linear actuator was proposed. The dynamic models of electromagnetic linear drive unit and active check valve were established. Based on the input flow curve of hydraulic cylinder, the characteristics of flow pulsation and flow rate of electromagnetic direct drive hydrostatic actuator were studied, and the effects of structural parameters and motion parameters of active check valve core on the dynamic characteristics of the actuating system were analyzed. The results show that reducing the diameter of valve seat and the stroke of valve core will reduce the maximum input flow of hydraulic cylinder; when the plunger starts moving and reaches the dead center position is synchronized with the opening and closing of the valve core, there will be no backflow and pulse in the system; compared with the passive flow distribution electromagnetic direct drive hydrostatic actuator system, the active flow distribution actuator system can improve the system net flow and suppress the system flow pulsation.