We study the CNC tube bender to better bending of thin-walled copper tube. According to the century periodical reports, Kunming Science University of Technology Li Qiang, et al. described in the article "copper thin-wall tube bending in common defects and preventive measures": thin-walled copper tube in the automobile circuit, for heat exchanger, air conditioners, refrigerators, aerospace industry and other equipment in the application is extremely broad. Bending of thin-walled copper tube production is generally in the CNC tube bender of cold roll forming, both bent core or non core bending, due to the wall brace buckling critical force is low for thin-wall copper pipe, bending parts often appear flat wrinkle deformation defects. These defects will not only weaken the pipe strength, reduce its carrying capacity, and it is easy to cause medium in the pipe flow unevenness of velocity, vortex and the bending part of the accumulation of dirt and other, the normal use of the impact the bending, thus eliminating defects of the bend tube is very necessary. To find out the reasons for the different types of defects, and to take preventive measures is particularly important.