Abstract: Basing on the expert system fuzzy identification method,fuzzy identification model for big pore throat was designed,in which characteristics of abnormal percolation throat were considered,and 6 cases were particularized:normal reservoir,high permeability zone,big fracture,incompletely and completely developing big pore throat.By integrating the flow rule and characteristic of diversified medium,using percolation mechanics and hydromechanics theory,a quantitative analysis and parameter calculation method of flow property along big pore throat was designed from the pore linear percolation to the coarse tube turbulent flow.By using this model,simple cubage and diameter of the big pore throat can be straight calculated,on the base of which the quantity and grain size of plugging agent can be made certain.