The utility model relates to a deepwater submarine pipeline buckle arrestor which is characterized by comprising a buckle arrestor body, wherein the buckle arrestor body is a cylindrical shell body, the inner diameter of the buckle arrestor body is smaller than the inner diameter of the submarine pipeline, and the outer diameters of the buckle arrestor body are divided into two first steps, two second steps and a third step in sequence according to sizes. The third step is located on the middle portion of the buckle arrestor body, the second steps are both arranged on the two sides of the third step, and the first steps are both arranged on the other sides of the two second steps. The outer diameter of each first step is smaller than the inner diameter of the submarine pipeline, the outer diameter of each second step is the same as the outer diameter of the submarine pipeline, and the outer diameter of the third step is greater than the outer diameter of the submarine pipeline. According to the deepwater submarine pipeline stopping and bending device, a complicated technology is not needed in the welding process, and the first steps can be used as a cushion in welding the submarine pipeline, therefore not only is the improvement of the welding quality of the submarine pipeline facilitated, but also the improvement of the buckling performance of the deepwater submarine pipeline stopping and bending device is facilitated. The deepwater submarine pipeline buckle arrestor has high buckling performance when being used in deepwater environment and the difficulty in welding is cut down, and thus the buckle arrestor can be widely used in the submarine pipeline in the deepwater environment.