The northwest entrance/exit passage tunnel of Guloudajie station on Line 2 of Beijing Metro is constructed by cutandcover method. However, due to the conflict between the completed passage tunnel and the existing sewage pipe line, the passage tunnel has to be lowered. Waterproofing curtain is installed between the piles of the opencut passage tunnel and the floor base of the passage tunnel is consolidated by means of jet grouting piles, which ensures the safety of the foundation pit during the renovation. The waterproofing scheme is optimized and the joint is well treated, which ensures the waterproofing effect of the works.