The invention provides a precise positioning system for a tunnel leading pipe shed. The precise positioning system comprises a guiding wall, a guiding pipe and supporting parts. The outer end of the guiding pipe extends out of the guiding wall and is detachably connected with a group of laser positioning parts; a drilling device is arranged in the guiding pipe in a penetrating mode; the laser positioning parts comprise at least two positioning plates arranged in parallel at intervals; circular holes are formed in the positioning plates; connecting lines between the circular holes correspond tothe center line of the guiding pipe; and the drilling device is provided with a drill bit and a drill pipe with limiting parts. The construction method of the precise positioning system includes thesteps that based on a laser rangefinder, the drilling distance is positioned through the circular holes of the positioning plates, space limiting is carried out according to the limiting parts on thedrill pipe, rectification adjustment is carried out through a guiding drill bit, and in this way, precise positioning of the leading pipe shed is combined. According to the precise positioning systemfor the tunnel leading pipe shed and the construction method of the precise positioning system, precise control of the drilling angle is facilitated, space displacement is limited in the drilling process, easy manufactured positioning elements, convenient use, easy and controllable implementation of the positioning method can both effectively save the working time and improve the construction quality.