Xuanwumen station on No.4 line of Beijing Metro is the first mined tunnel that undercrossing existing station in China. Due to the space between the two stations is too narrow and the existing station must be normal operating, the construction is a huge challenge. The construction schemes selection of this project are analyzed from numerical simulation and construction experience. The successful completion of this project shows that the selected construction scheme is reasonable. This construction scheme can provide reference for the similar projects construction in the future.