During normal operation, it is very vulnerable to external disturbances, so the analysis and research of different operating conditions have significant impact on wind turbines. Based on finite element analysis software ANSYS, a two-dimensional electromagnetic field model of doubly fed induction generator (DFIG), whose capacity is 1.5MW and is installed in a certain wind farm, is established. During normal operating conditions, grid voltage unbalance and wind speed mutation conditions to simulate and analyze the doubly-fed generator air gap flux density, magnetic field lines distribution,we will obtain the effects of different conditions on the doubly-fed generator. The simulation results show that grid voltage unbalance conditions and wind speed mutation conditions, doubly-fed generator and air gap flux density will change, but a significant distortion occurred in the former flux density, magnetic flux leakage increases, the loss increases.