Cooling device for exhaust pipeline of aero-engine test bed

The invention discloses an aero-engine test bed exhaust duct cooling device which comprises a cooling cylinder, a butt joint sleeve is arranged at the left end of the cooling cylinder, a set of rotating blades are rotationally installed in the cooling cylinder and fixedly connected to a core seat, and the ends, away from the core seat, of the rotating blades are rotationally connected with rolling wheels. A group of roller seats are fixedly connected to the circumferential inner wall of the cooling cylinder, each roller seat comprises a pair of check rings, the rollers are arranged between the check rings in the same group, branch pipes are fixedly installed on the back faces of the rotating blades, a group of spray heads are arranged on the branch pipes, and a rotating connector is fixedly installed in the center of the core seat and connected with the tail ends of the branch pipes; the rotary joint is rotationally connected with the water supply pipe. The rotating structure drives the spray head to rotate t