In industrial production, water is removed from nitrocellulose by applying a certain pressure. During this process, nitrocellulose deforms: pores in the particle layer shrink, accompanied by liquid discharge. Currently, research on the deformation behavior of different nitrocellulose materials under continuous pressurization is lacking. In this paper, multi-stage pressure loading tests were conducted on two types of nitrocellulose. A material compressibility equation was established to explore the relationship between their solid volume fraction and pressure. The Terzaghi-Voigt model was used to describe the two-stage consolidation process of the materials under constant stress. On this basis, the primary consolidation stage of nitrocellulose was studied, and an instantaneous compression equation was established to describe its short-term compression deformation process. The results show that the two types of nitrocellulose materials follow the same consolidation law under pressure; as pressure increases, the consolidation stabilization time of the materials gradually prolongs, and the dewatering process gradually shifts from instantaneous drainage to creep dominance; the compressibility equation and instantaneous compression equation established in this paper are also effective for different pressurization processes.