The invention discloses a pre-reinforcement and excavation construction method for a tunnel entrance segment of a
loess tunnel passing through a slip
mass. The method comprises the following steps offirstly, tunnel body soil layer pre-reinforcement, secondly, tunnel entrance construction of the tunnel, thirdly, excavation and preliminary bracing construction of the reinforced tunnel segment, andfourthly, excavation and preliminary bracing construction of the rear tunnel segment. By means of the method, design is reasonable, construction is simple and convenient, and the use effect is good; before excavation, cemented soil stirring piles are adopted for carrying out reinforcement treatment on the
loess stratum of the construction area where the tunnel entrance segment of the tunnel is located in advance, the reinforcement length and reinforcement depth are effectively limited, loose soil of the tunnel body of the tunnel is solidified in advance, it is ensured that the construction process of the tunnel entrance segment of the tunnel passing through the slip
mass is safe and reliable, and the structure of the tunnel entrance segment, formed through construction, of the tunnel is stable; and meanwhile, a three-step excavation method is adopted for excavating the tunnel entrance segment of the tunnel, it can be ensured that the excavation process of the tunnel entrance segment ofthe tunnel passing through the slip
mass is safe and reliable, and the influence on stability of soil
layers around the tunnel is small.