In order to evaluate the effect of sponge city reconstruction in Xiaozhai Old Urban Area of Xi’an, a 2D urban storm flood model coupled with pipe network module was used to simulate the waterlogging situation before and after sponge city reconstruction in Xiaozhai Old Urban Area under different rainfall return periods. According to the comparison of the simulated distribution, volume and area of the waterlogging before and after the sponge reconstruction under different rainfall return periods, it is found that the waterlogging situation under each return period has been improved after the sponge reconstruction, and the sponge reconstruction has an obvious effect on the alleviation of waterlogging in the old urban area of Xi’an.