To overcome the difficults caused by uncertainties of material and load in numerical analysis of structure with cracks and to improve the accuracy and efficiency of numerical calculation,a fuzzy finite element analysis method of B-spline wavelet on the interval(BSWI) is put forward by combing the fuzzy theories with wavelet finite element.Fracture elements of dummy nodes are embedded into the wavelet finite element model with cracks,fuzzy equilibrium equations on the basis of finite element of BSWI are established,and the fuzzy equilibrium equations are solved by using λ level set and decomposition theorem.Subsequently,the membership function values of stress intensity factor with different crack lengths are calculated by using virtual crack closure technique,and the calculated results are compared with analytical solution.The analysis results show that the proposed method can accurately reflect changes in structural response with fewer elements and can be a new way for engineering fracture analysis of complex structures with uncertainties.