Based on the main cable of Liangqing Bridge in Nanning, the key factors of the breakage of the fixed binding tape were studied by using the method of field production verification and comparison. The results show that the pre-wrapping tension of the fixed binding belt, the speed of winding up of the upper wall of the cable strand, the storage time interval of the cable strand, and the temperature are the key factors that cause the loose yarn, deformation and relaxation of the cable strand in the production process of the main cable strand.