Biomass pyrolysis is a high value-added process of biomass conversion. The direct pyrolysis experiments of no crushed cotton stalks were conducted. The results showed that the solid product and fixed carbon (FC) content were maximum when pyrolysis temperature was in 400℃. As the pyrolysis reaction proceeded, the higher temperature increased and the solid products reduced, and the ash content in the products increased accordingly, which led to a decrease in fixed carbon (FC) content after 400℃. In order to determine the optimum technological parameter of pyrolysis, an orthogonal experiment was conducted.The maximum product yield of 49.98% was obtained with 5℃/min of heating rates, 400℃ of optimum pyrolysis temperature, and 2h of holding time.