A finite element model of non-uniform corrosion-expansion-induced cracking of a concrete cover was built using the extended finite element method(XFEM)and interference fit assembly. The calculated results show that a cracking band including several microcracks occurred across a range of 10° to 30°, adjacent to steel bars on their left and right sides, and developed symmetrically in the backward direction away from the medial axis of the steel bars. With increasing degree of corrosion, a diagonal main crack occurred in the crack band, resulting in wedge-shaped destruction of the concrete cover. By means of the secondary development of ABAQUS, the length of corrosion-expansion-induced cracks was obtained, and an exponential relationship between the crack length and the corrosion ratio of steel bars was deduced. The cracking development can be divided into three stages, corresponding to the occurrence of the embryonic zone, extending zone, and gradual development zone of cracks, and the corrosion ratio of steel bars, when cracks enter the gradual development zone, can be used to evaluate the durability of structures. The accuracy of the calculated results was verified by comparison with damage of bridges on the Guanghui Expressway induced by concrete cover desquamation.