The repeated cutting function of mid-wire makes the loss of molybdenum wire increase after processing the same area of work piece, which affects the accuracy and luminosity of work piece. Most of mid-wire walking on the market is a pulse power supply extended from the original fast-wire cutting. The base of the pulse power supply does not adapt to the characteristics of the repeated cutting of mid-wire; mid-wire walking reduces the running speed of molybdenum wire and also reduces its operation speed. The flutter of molybdenum wire in the process of processing is helpful to improve the accuracy and surface photometry of the workpiece. The stability of the leading wheel is the decisive factor for the flutter of molybdenum wire.

The surface luminosity of the workpiece processed after repeated cutting is not as good as that of the workpiece cut by the fast wire-walking line of the new guide wheel; the gemstone wire-guiding device is added to the middle wire-cutting, mainly referring to the guide structure of the slow wire-walking and piercing machine. One common point between the slow wire-walking and the piercing machine is that the traveling speed of the electrode wire and the electrode is very slow, but the first cut of the middle wire-cutting is very slow. The running speed of the wire is 40-60 times that of the slow-moving wire. The high-speed conflict and high temperature caused by the running speed also make the gem wire guide on the slow-moving wire and piercing machine unsuitable for the requirements of the middle-moving wire, which quickly damages and affects the processing effect.