In order to reduce the harm of the nicotine to human body during the suction, the distribution of nicotine interception and flue gas temperature in the cellulose acetate cigarette filter under ISO suction mode was simulated via the standard k-ε turbulence model, SIMPLE algorithm and porous medium model. The results showed that the total enthalpy of air decreased gradually with the time, and the nicotine spread quickly and decreased gradually along the axial direction, because nicotine temperature gradually decreased and nicotine slowly moved down when spreading to the smoking end. Moreover, the nicotine also distributed discretely, which reduced the nicotine intercept efficiency because of the fierce Brownian motion under thermophoretic force along the radial direction. Meanwhile, it is found that the simulation intercept efficiency of cellulose acetate cigarette filter was 30.59%, which was close to the experimental efficiency under the same conditions, and the results can provide theoretical basis for the optimal design of the filter.