The invention provides a construction method of a cast-in-place decorative finish bare concrete wall. The construction method comprises the steps of delimiting a construction area on the ground, preparing a wall skeleton, preparing a plurality of wall formworks, hoisting the wall formworks, preparing bare concrete, removing all impurities in the wall skeleton and the wall formworks, pouring cementmortar, pouring the bare concrete into the wall skeleton several times, vibrating the bare concrete, curing the cast-in-place decorative finish bare concrete wall, and dismantling protective materials. According to the technique scheme of the construction method, the wall formworks are made from N-shaped steel beams and punched and cold bend C-shaped structural steel, the flatness of a panel is high, at same time, a plurality of wall penetrating screws are adopted, the structural strength of an existing supporting system of the wall formworks is greatly enhanced, the flatness of both sides ofa pouring wall body is effectively ensured, and compared with the prior art, the construction method has the advantages of convenient installation of the wall formworks, good quality of the pouring wall body, low cost, saving of raw materials, shortening of construction time, reduction of environmental pollution and the like.