The invention discloses a concrete pouring construction method for an underground gallery. The concrete pouring construction method comprises the step of bottom slab concrete pouring, side wall concrete pouring and top slab concrete pouring, an inner formwork and an outer formwork of the side wall are erected to the top at a time, and the step that concrete is poured onto a bottom slab, a side wall and a top slab after scaffolds and top slab formworks are installed completely. Due to the fact that the bottom slab concrete, the side wall concrete and the top slab concrete are poured at a time, stagnant water steel plates do not need to be installed through welding, so that the material cost of the stagnant water steel plates and welding rods as well as the labor cost for welding the stagnant water steel plates are reduced, the turnover rate of the steel formworks and the scaffolds is increased, the construction cost is greatly reduced, and the construction period is shortened; in addition, no horizontal construction seam exists in the wall, and the waterproof performance is improved.