Based on the sensitivity analysis and probabilistic load flow calculation，a probabilistic method of fast static security analysis is presented for the planning of power system containing wind power.The randomness of wind farm output，the unscheduled unit outages and the fluctuation of load forecast are taken into account in this method.The sensitivity analysis is used to simulate the branch outages，and the probabilistic load flow calculation considering the changes of grid infrastructure is applied to realize the probability analysis.The accuracy of this method is improved by using the sensitivity matrix that considering the changes of grid infrastructure.In order to accelerate the calculation，the theories about semi-invariant and Gram-Charlier series expansion are applied to avoid the complex convolution calculation.Simultaneously，the technology of contingency sequencing is adopted to avoid analyzing the outages of each branch，which reduces the calculation amount.The simulation results obtained for the IEEE14-bus test system containing wind farms demonstrate the effectiveness of the proposed method.