Abstract: In order to utilize agricultural waste of tobacco straw effectively, tobacco straw was used as raw material, and cellulose nanocrystal (CNC) was prepared by ammonium persulfate oxidation method combined with ultrasonic method. The products were characterized by scanning electron micrograph (SEM), transmission electron microscope, Fourier transform infrared spectrometer, X-ray diffraction (XRD), thermogravimetric (TG) and rheological analysis, and it was made into a single smoke for sensory evaluation. The results showed that the CNC was prepared as carboxyl-type with short rod-like structure, diameter of about 10 nm, and length of 50～60 nm; XRD analysis showed that it retained natural cellulose Ⅰ structure with a relative crystallinity of 60.86%; the initial pyrolysis temperature of CNC was 201.47 ℃, and the thermal stability was lower than that of tobacco straw. The steady-state rheological test showed that the viscosity of CNC suspension increased with increase of solid content, while the shear thinning behavior increased with the increase of the viscosity. The dynamic rheological test showed that CNC suspension exhibited obvious gel behavior when the solid content was 1.76%. When the amount of CNC added was 0.6%, the comprehensive score was the highest.