The invention discloses a modern assembly type constructional engineering reinforcement cage stirrup compressing and cutting device which comprises a base. The base is provided with two barrel supporting bases; the two barrel supporting bases are provided with a spiral winding barrel assembly; and an outer cutting assembly and a stirrup compressing device are arranged on the positions, corresponding to the spiral winding barrel assembly, of the base. By the adoption of the technical scheme, the modern assembly type constructional engineering reinforcement cage stirrup compressing and cutting device has the remarkable effects that reinforcements are wound into a plurality of circles of spiral reinforcements on a barrel, compression parts compress the spiral reinforcements on the barrel and keep the spiral reinforcements stable, the spiral reinforcements are directly cut on the barrel through cooperation of an outer cutter and an inner cutter to obtain a plurality of semi-finished stirrup products, finished products can be obtained after welding, the cutting efficiency is greatly improved, and the labor intensity is relieved.