Disclosed are a glycine reuptake inhibitor and the use thereof. The glycine reuptake inhibitor is a compound of formula I, or isomers, pharmaceutically acceptable salts or solvates thereof, wherein R1 is one or more groups selected from hydrogen, halogen, C1-6 alkyl, C1-6 alkoxy, nitro, cyano, amino, hydroxyl, C1-6 haloalkyl, and C1-6 haloalkoxy; R2 is selected from hydrogen, C1-6 alkyl, C1-6 alkoxy, C1-6 haloalkyl, and C1-6 haloalkoxy; and each of R3 and R4 is independently selected from hydrogen, halogen, C1-6 alkyl, C1-6 alkoxy, nitro, cyano, amino, hydroxyl, C1-6 haloalkyl, and C1-6 haloalkoxy.