The effects on physical characteristics, chemical characteristics of tobacco stem, tobacco stem extraction rate and pulp properties after high pressure steam and conventional pretreatiment were investigated in this study. The results showed that the contents of hot water and ethanol soluble in the stem of the high pressure pretreatment increase to a certain extent, and the efficiencies of extraction and the production line were improved. The amount of fine fibers produced by the high pressure pretreatment after the defibrination was less, and this was beneficial to the improvement of the product yield. The dynamic filtration performance of the stem pulp after the high pressure pretreatment was better than that of the conventional pretreatment, which was good for paper making.