For the model of single copula function containing larger distortion defects in describing wind power correlation,puting forward to construct comprehensive Copula function model to depict the correlation structure of strategy, and EM method is used to estimate the value of the related parameters in the model. Two adjacent wind farm in a certain area of actual historical output data as the foundation, by comparing different combination function of goodness of fit check, select the most optimal comprehensive Copula function, and apply it in the system of the probabilistic power flow calculation. Making the branch active power and the node voltage of the two probability density curve, compared with single Copula function of income curve, verified the effectiveness and feasibility in modeling of wind farm output.