Several kinds of artificial biological materials have the characteristics of low production cost, low mass density, controllable morphology, safety and environmental friendliness, and better extinction ability in the visible and infrared bands, which can be used as new extinction materials to make up for the shortage of inorganic extinction materials. With the increasing demands for new biological extinction materials in military and civilian fields, the flocculent biological particles in the biological extinction material are equivalent to bullet rosette particles. According to Newton′s second law and gradient transport theory, the sedimentation and diffusion models of biological extinction material were established. The structures of flocculent biological particles and wind speed and atmospheric stability′ influences on aerodynamic characteristics of biological extinction materials were discussed. The results indicate that the structures of flocculent biological particles are controlled by the number of branches, as well as their length and radius. Under given conditions, the settling rate of flocculent biological particle decreased by 50％ compared with that of equal volume sphere particle. And the max covering area of smoke can reach more than 20 m2. The model provides a theoretical basis for the further development and use of biological extinction materials.