The invention provides a prefabricated concrete U-shaped groove mold and a using method thereof. The prefabricated concrete U-shaped groove mold comprises an inner template, an outer template and movable sealing sides, wherein sections of the inner template and the outer template are U-shaped; the inner template is arranged in the outer template; the outer template and the inner template are encircled to form a pouring space with a U-shaped section; one movable sealing side is mounted in a space corresponding to each of two ends of a U shape of the pouring space; the movable sealing sides aredetachably connected with the inner template and the outer template. The prefabricated concrete U-shaped groove mold achieves the effects of reducing the consumption of shaping templates, increasing the turnover rate of the shaping templates, reducing the occupied area and accelerating the construction speed; the prefabricated concrete U-shaped groove mold is simple to operate and is practical andeffective; through popularization and application, the cost can be reduced; the production efficiency can be improved.