The invention relates to the technical field of heavy-duty shell ring manufacturing, and provides a device for detecting the shape of an edge part of a heavy-duty shell ring in a rolling process. Thedevice comprises a first detection device and a second detection device. The first detection device comprises a first support device, and the first support device is provided with four photoelectric range finders. The second detection device comprises a second support device, and the second support device is provided with two photoelectric range finders. The invention also discloses a method for detecting the shape of the edge part of the heavy-duty shell ring in the rolling process, and the method employs the above detection device for detecting the external diameter of the heavy-duty shell ring in the rolling process. The detection device is low in maintenance difficulty, is high in operability, can prevent the impact from a thermal load and the dust in the rolling process from affectingthe detection equipment, is long in service life, and is high detection precision. The method can achieve the detection of the size of the shape of the heavy-duty shell ring based on the detection device, and is used for the shape closed-loop control system of a rolling machine, so as to produce qualified heavy-duty shell ring.