With the preliminary development of large-scale and cluster wind power base, wind power has been developed rapidly as a clean and efficient energy. But extensive wind farms are connected to the power grid in a short time, which brings disturbance to the power balance and cause the instability of the voltage of the power network. According to the voltage control problems of wind farm integration, in this paper, the mechanism of static voltage stability of large-scale wind farm group is studied. Through adjusting the reactive power of the wind power generator, the transformer taps of boost substation and the reactive power compensation device are timely adjusted on the basis of existing adjustment method for voltage. A reactive power/voltage control strategy based on hierarchical management is further proposed, which is embedded into the voltage/var management platform (VMP) for wind farm. It is found that the control strategy can improve the performance of reactive power during the period of low voltage ride through, and improve the stability of the reactive power and voltage of the wind farm, and also avoid the generation of power oscillation by the test-in-place of a certain area in Xinjiang. The study provides a basis and reference for theoretical research and practical engineering on reactive power coordinated control strategy for wind farms. This work is supported by National Natural Science Foundation of China (No. 51267017).