Good working environment in manufacturing is an important guarantee of machining quality, and has an important impact on precision machining and ultra-precision parts machining quality. In the actual processing of ultra-precision parts, the dust in the air is larger than the abrasive particles, which sometimes causes damage to the processed surface and affects the processing effect of the abrasive particles, so the air purification before ultra-precision machining is needed. Dust with a diameter of more than 0.5m is an important factor affecting the quality of ultra-precision machining. Therefore, the amount of dust with a diameter of more than 0.5m in 1ft3 volume is generally taken as the benchmark to define the air purification grade.

Usually, the air purification grade of ultra-precision machining must reach 100~10000 grade. Cleaning is the most common way of air purification. The processing workshop after purification is called clean room and super clean room. Generally speaking, there are two main types of purification, one is overall purification, the other is local purification. Local purification is economical, through the positive pressure of clean air into the workbench and other local processing area, prevent the inflow of external air, to achieve purification. Due to the staff's hair, work clothes and so on May bring dust, before entering the work, the staff must clean the outdoor replacement of special clothes, wet by the wind, effectively avoid the impact of dust on the quality of processing.