The later constructed railway may have great influence on the former constructed shield tunnel. For this case, the paper analyzed two types of foundation treatment measures, including cement mixing pile and pile- plank structure. According to the results of theoretical calculation and numerical simulation, the deformation of shield tunnel with cement mixing pile reinforcement is above the protection standard of subway while the defor- mation of shield tunnel with pile-plank reinforcement can control the deformation of the tunnel. The research may provide reference for similar projects in the future.