The impact of wind power generation on the load modeling in the distribution network is studied using MATLAB and based on measurement-based method. It is pointed out that the synthetic load of distribution network including wind power generation can be described by a generalized composite load model combining asynchronous machines and static loads. To precisely reflect the impact of wind power generation on the composite load model， the percentage of dynamic load must be extended to any real number. The validity of this composite load model of any percentage of dynamic load is testified by modeling three typical operation styles with different compositions of wind power generation and load.