The invention relates to a fin stripper of a fin tube at the heating surface of an afterheat boiler. The fin stripper comprises a fin cutting device and a fin clamping and removing device, wherein the fin cutting device comprises a handle, a stress body and a semicircular clamp, the top of the handle is connected with the bottom of the stress body, the arc-shaped bottom of the semicircular clamp is fixedly arranged at the top of the stress body, two tail ends of the semicircular clamp are connected with two knife blades vertical to tail ends, the knife blades are integrally connected with the tail end of the semicircular clamp or are detachably connected with the tail end of the semicircular clamp through fixing screws, the fin clamping and removing device comprises an L-shaped rotating handle, the tail end of the short edge of the L-shaped rotating handle is a sharp end, in addition, the middle part of the sharp end is provided with a clamp opening, the top of the handle is embedded and connected with the bottom of the stress body, and the inner diameter of the semicircular clamp is 1 to 5mm greater than the outer diameter of the fin tube. The fin stripper is used for stripping fins of the fin tube, the operation is convenient, in addition, the fin stripping operation difficulty can be effectively reduced, the fin stripping efficiency is improved, and the fin tube is not easy to get chiseled damage.