Rolling diameter measurement, breakage detecting and tension control method for printing body and colored tape

The invention provides a rolling diameter measurement, breakage detecting and tension control method for a printing body and colored tape. According to the rolling diameter measurement, breakage detecting and tension control method, a printing head motion device, a colored tape driving device, a photoelectric module and a colored tape tension detecting module are included; and due to the fact that the photoelectric module and the colored tape tension detecting module are arranged on the colored tape driving device of the printing body, the photoelectric technology is used, motion of a motor is used in a matched manner, the rolling diameter of printed colored tape and the rolling diameter of non-printed colored tape can be detected, and whether the colored tape breaks or not can be detected in the printing process. By means of the rolling diameter measurement, breakage detecting and tension control method, the rolling diameter of the colored taper is measured and calculated, an operator can conveniently replace the colored tape at any time, the colored taper can be sufficiently used, waste is reduced, and the excellent printing quality is guaranteed.