Machining tool special for heat exchange tube end cutting

The utility model provides a machining tool special for cutting the pipe end of a heat exchange pipe. The positioning shaft is connected with the knife rest rod; the positioning shaft is sleeved withthe positioning sleeve, and the positioning sleeve and the tool rest rod are arranged at intervals; the knife block is telescopically arranged on the knife rest rod, part of the knife block extends out of the end face, facing the positioning sleeve, of the knife rest rod, and the knife rest rod drives the positioning shaft, the positioning sleeve and the knife block to rotate synchronously; and when the heat exchange pipe is arranged on the positioning sleeve in a sleeving mode and the to-be-machined pipe end of the heat exchange pipe is located between the tool rest rod and the positioning sleeve, the tool block rotates relative to the heat exchange pipe so as to cut the to-be-machined pipe end. The problem that in the prior art, a drill bit easily damages the inner wall of a heat exchange tube in the cutting pro