The measures to enhance transient voltage stability of induction generator based wind farm are studied in this paper. Constant speed wind turbines equipped with induction generator is the most widely used technology in the world so far. The local grid voltage stability will be reduced due to the integration of induction generator based wind farm because the high demand of reactive power absorbed by induction generator. The SVC with its controller model and pitch control model is set up in the power system simulation program DIgSILENT/PowerFactory in this paper. The model validity and the contribution to the transient voltage stability are verified by power system simulation containing large wind farm. Power system simulation results show that the SVC can assist the induction generator restoring the voltage rapidly in the duration of power system large disturbance， ensuring both the voltage stability of the grid and the continuous operation of the wind turbines. They also demonstrate that pitch control of constant speed wind turbines can effectively reduce the wind turbine mechanical power， preventing the wind turbines from over-speeding and transient voltage instability in the duration of power system large disturbance. Finally， it is concluded that the adoption of the SVC and pitch control enhances the transient voltage stability of induction generator based wind farm， ensures the continuous operation of wind turbines and the security and stability of the power network.