Abstract: Generally, the dangerous position in fatigue analysis of a structure is around the screw holes. Thus, defining the position of the screw hole severely loaded and calculating the max. tangential stresses by its side compose the most important parts in estimating fatigue life.By using the stress severity factor method （SSF）, in which the stresses caused by transfer load and by-pass load are simply summed, the actual stress distribution of hole side can't be found in many cases. Therefore, the elasto-plasfic contact analysis considering different load combinations and clearance fits is simultaneously introduced in order to get more accurate results. This paper presents a series of te chnigues including structural detail analysis, selection of the screw hole severely loaded and the elasto-plastic contact analysis of screw-hole clearance fit. It is worth noting that in the paper the initial stress method of deformation theory is used for elasto-plastic analysis, the simplex type algorithm of linear programming is used for contact analysis and they are closely coupled together, so that the defect of high computational cost due to alternate iteration between nonlinear analysis and nonlinear material analysis is eliminated. In addition, the method provided can improve the solution convergency.Some conclusions based on lots of examples are of benefit to design of fastened joints. And, the corresponding tests have; proved that the method is reliable and can meet the engineering precision request.