Abstract:The turbulent diffusion and thermophoresis of particle in the process of gas-liquid cross flow used to absorb PM 2.5 were investigated by experiment and simulation.The stochastic trajectory model was proposed to investigate the motion situation under thermophoresis of particle and the simulation results were compared with two detection methods of chemical analysis and gravimetric analysis.The results showed that the trap rate of particle by chemical analysis was basically the same as it by gravimetric analysis,and the consistency of two detections of particle concentration was verified.When the gas velocity rate was 1 m·s^-1 and the turbulent diffusion model was also considered into numerical computation,the relative deviation between numerical simulation and experiment was reduced from -60% to ±30%. which proved that the turbulent diffusion was one of the most important factors affecting the particle removal in the system.