The invention discloses a pressure release valve for a cooling pipeline of an ultra-high molecular weight polyethylene pipe extruder. The pressure release valve comprises a cooling pipeline connector, the cooling pipeline connector is provided with a first air pressure telescopic rod, and the first air pressure telescopic rod is provided with a second air pressure telescopic rod; the cooling pipeline connector is further provided a plurality of steam outlets and an exhaust pipe, and opening and closing of the steam outlets and the exhaust pipe are controlled by the first air pressure telescopic rod and the second air pressure telescopic rod; the first air pressure telescopic rod and the second air pressure telescopic rod are connected in a high-damp sliding mode; the steam outlets are provided with metal gauze meshes respectively. According to the pressure release valve for the cooling pipeline of the ultra-high molecular weight polyethylene pipe extruder, the connector is provided with the two air pressure telescopic rods, the two air pressure telescopic rods extend to the external when the pressure in the pipeline is increased and can open the steam outlets and the exhaust pipe on the connector for releasing the pressure, and therefore the cooling pipeline is prevented from being expanded and cracked.