Bending machine for small-bore medium pipelines and using method of bending machine

The invention discloses a bending machine for small-bore medium pipelines and a using method of the bending machine. The bending machine comprises a working plate which is arranged on a working panel of a transmission case and is connected with a transmission chain of the transmission case, the working plate is provided with a center wheel installed on a center pin shaft and a bending wheel installed on a bending pin shaft, the wheel edge of the center wheel and the wheel edge of the bending wheel are respectively provided with a wheel groove of which the section is in a semi-circle shape, the semi-circle diameter of each wheel groove is matched with the diameter of a bent pipeline, the two sides of the working plate are respectively provided with a piece of stop iron used for installation of stop pin shafts, each piece of stop iron is provided with mechanical limiting positions which are used in cooperation with a limiting pin shaft on the working plate, and the edge of the working plate is provided with a steel angle contact which is used in cooperation with a travel switch which is connected with a switch box and synchronizes with a switch button. By means of the bending machine, the problem that differences exist between angles obtained by an existing bending method and angles used on spot is solved, secondary hand finishing is not needed, labor intensity is relieved, and working efficiency is improved.