The invention discloses a pipe gallery foundation pit assembly type integral translation supporting system and a construction method. Enclosure structures are arranged on the two sides of a pipe gallery foundation pit in the length direction, coping beams are arranged at the tops of the enclosure structures, concave platforms are arranged on the sides, close to the foundation pit, of the coping beams in the length direction, the supporting system comprises connecting beams, steel supports, jacks, longitudinal guide rails and idler wheel assemblies, transverse positioning grooves are formed inthe longitudinal guide rails at intervals, the idler wheel assemblies are positioned under pushing of the jacks, and the idler wheel assemblies can drive the connecting beams to move along the longitudinal guide rails. According to the supporting system and the construction method, the characteristic that the supporting lengths and intervals of the underground pipe gallery foundation pit in the longitudinal direction are consistent is fully utilized, the rapid, convenient and safe supporting system and the construction method are provided for the underground pipe gallery foundation pit in a targeted mode, the supporting construction efficiency and the earth cutting efficiency are greatly improved, and meanwhile, the beneficial effects of saving materials, saving energy and being environmentally friendly are achieved; and good economic and social benefits can be generated.