Abstract: Collecting micron aerosol particles with microfluidic inertial impactor is a new filtration way, which made up the deficiencies of existing filtration methods and the feasibility has been demonstrated. But airflow pressure loss in the existing microfluidic inertial impactor is large and its processing technology is complex. A new type of microfluidic inertial impactor was designed and studied, and CFD software was used to simulate the characteristics of flow fields and performance of microfluidic inertial impactor. A mathematical model was established. The gas phase used the laminar model and the particles phase used discrete phase model (DPM). By simulation the effects of the impactor with different structure parameters on the collection efficiency were analyzed. The results show that the turning angle and impactor size D have great influence on collection efficiency. The smaller the turning angle, the higher the collection efficiency, and when D≤1/2, the efficiency curve is substantially retained.