In order to study the influence of different excavation on small interval tunnels under bias pressure,based on the Yangjiaping tunnel project in Chongqing, this study used Midas-GTS NX software to establish a finite element model of the tunnel and investigated the effects of different excavation methods for small interval tunnels under biased pressure on surrounding rock stress, arch settling, and abutment uplift before and after the reinforcement of the middle rock wall. The research results showed that grouting reinforcement of the middle rock wall of the small interval tunnel can improve the soil strength and avoid the dislocation of the middle rock wall. The horizontal displacement of the middle rock wall, arch settling, and abutment uplift of the small interval tunnel excavated using the CD method were better than those of the CRD method and the annular excavation method with the core soil. The excavation of the small interval tunnel under biased pressure using CD method can effectively reduce the influence of the trailing hole excavation on the leading hole.