The utility model relates to a building back throwing structure construction protection device which is composed of a stand column, a protection plate, a turning plate and a pulley. The pouring deviceis characterized in that reserved holes allowing the stand columns to penetrate through are formed in the upper-layer ground to be poured, the protection plate is fixed to the stand columns above theupper-layer ground, pulleys and turning plates are arranged on the four edges of the protection plate, and the turning plates are located above the pulleys; the adjacent stand columns between the lower-layer ground and the upper-layer ground are connected through detachable connecting rods. According to the construction protection device for the back throwing structure of the building, falling objects on the upper portion can be effectively prevented from hitting workers on the upper-layer ground, it is guaranteed that the workers conduct steel bar binding and concrete pouring operation on the upper-layer ground in a safe state, the working efficiency is improved, the labor intensity is reduced, and the beneficial effects are remarkable.