The entrance of Dongchongli tunnel is located at Ⅴ class surrounding segment with the geological fracture development and abundant groundwater, and the tunnel was designed to construct on one side of the mountain body. As the side pressure was not be considered in the design, the fracture and sliding occurred at the side of the tunnel and the front slope during the tunnel construction; cracking and dislocation happened in the second grouted lined concrete in the borehole and the turning point appeared in situ monitoring data. By the study and analysis, it was determined that all these were caused by side pressure. According to the field situation, the analysis and evaluation were made on several schemes; by the comparison, slant grouting long pipe roof was adopted to solve the side pressure with satisfied effect.