Abstract: Stress-strength Integral method is the basis for structure reliability evaluation,but this method can not work properly when it is used to structure fatigue reliability estimation as the important parameter-material's equi-life strength-can hardly be obtained.A numerical approach based on the fuzzy probability integral method was studied.This method can give the structure reliability directly without the need of the equilife strength.A case study indicates that this approach is effective,and it is easy to implement and suitable for engineering applications.