Compressed air treatment (drying, filtration, oil removal) serves as the "purification hub" of the air compression system, directly determining air quality. In food and pharmaceuticals, oil-free and moisture-free clean air ensures safe filling and packaging; in electronics and semiconductors, micron-level filtration prevents particle contamination on wafers; in automotive painting, refrigerated or desiccant dryers prevent paint surface bubbles; in chemical plants, pneumatic instrumentation relies on stable dew points to prevent icing and misoperation; in laser cutting, refrigerated dryers reduce lens condensation loss. With the advancement of ISO 8573 standards and the growing adoption of variable frequency oil-free compressors, air treatment is evolving toward lower dew points, zero-purge operation, and intelligent monitoring, becoming a key enabler of industrial quality improvement and energy conservation.