In order to avoid offshore wind turbine off grid operation caused by grid voltage sag, the control strategy of dual PWM full power converter for direct drive permanent magnet synchronous with offshore wind power system is analyzed, a scheme of Low Voltage Ride Through (LVRT) for offshore wind turbines during grid-connected operation is presented based on Super-Capacitor Energy Storage System (SC_ESS). By paralleling super-capacitor energy storage system on the DC side of the bidirectional converter, this paper uses the super capacitor to stabilize the power balance during the grid fault and ensure the stability of the DC side voltage; it adopts static var compensation operation mode of grid-side converter to prior output reactive current and provide reactive power support to the grid. Simulation results show that under system fault, the presented scheme can efficiently restrain the DC side overvoltage, provide reactive power to the power system, speed up the restoration of power grid fault, and improve the LVRT capability of the offshore wind power system. This work is supported by National Natural Science Foundation of China (No. 51407013).