Basis weight and moisture content are two important parameters of paper's quality. We can preferably pledge quality of production, increase output, economize material, save energy sources through control the two parameter Computer control system for controlling the basis weight and moisture content of paper machine has a very complicated configuration, more disturb, end great pure lag. In this paper, we analyse the arts and crafts flow of the papermaking system, and model using Petri net. We have simulated and prove that the model is advantage.