Traditional chemical-machinery producing mainly took the refiner as the primary refining equipment. Extrusion pulping was the reformation of traditional refining pulping. The different equipments and processes resulted in the different characteristics of wastewater inevitably. This article aimed to compare the characteristics and biochemical treatment methods between conventional chemical-mechanical pulping and extrusion pulping, and then discuss the biochemical treatment advantages of extrusion pulping wastewater. The result shows that: the wastewater from the extrusion pulping has lower concentration of tiny fiber, load suspended matter, wastewater temperature and effluent discharge. And thus make a simpler process, a lower cost and a better effect of the wastewater treatment.