Most companies producing raw materials for other companies usually have a mass production system with a limited number of buyers. Optimization of the manufacturing process for this type of production system will have a big impact on the business competitive power. Pulp industry is a raw material industry consuming a huge amount of electric power. Thus, optimization of its production process is very important to reduce its manufacturing cost. In this paper, DOE(Design Of Experiments) is used to optimize the refining process of the pulp production system for practical field application. And the results are further analyzed not only to improve the pulp quality but also to accumulate knowledge on the process for future innovation.