In this study, the effect of thermal mismatch stress on the surface crack propagation of thermal barrier coatings was investigated by using extended finite element method (XFEM). The results show that the location, slope angle and length of crack have a significant impact on crack propagation length, energy release rate and stress level at crack tip under the influence of thermal mismatch stress. The crack length is the longest and the energy release rate is the largest in the valley for the same initial crack. The larger the slope angle is, the shorter the length of crack expansion is but the larger the strain energy is. The larger the initial crack length is, the longer the crack growth length and the faster the expansion rate is, and the greater the energy release rate is. The crack propagation affects each other under the condition of multiple cracks.