The invention discloses a cable tie cutting mechanism and an application method. The cable tie cutting mechanism comprises a protective cover, a blade, a first barrier piece, a first rolling shaft, afirst connecting piece, a bent pin, a first pin shaft, a second rolling shaft, a second barrier piece, a pull rod, a short spring, a fixing support, a scale display, an adjustment knob, a shell, a handle, a second connecting piece, a third rolling shaft, a tool bar I, a second pin shaft and a tool bar II. The cable tie cutting mechanism is easy and convenient to operate and good in cutting effectand aims at solving the problems that in the manual operation process, a cable tie cut is rough, and work efficiency is not high; and the utilization rate of the cable tie cutting mechanism is increased, practicability of the cable tie cutting mechanism is improved, and therefore, the cable tie cutting mechanism has wide application value in the technical field of cable tie devices.