Based on the non-flush grading test, the influence of inlet pressure and feed concentration on the grading effect was studied. It was considered that the relationship between the inlet pressure and the split ratio almost met the needs of the polynomial regression relationship, and the relationship between the inlet flow rate and the inlet pressure was approximately linear; when the inlet pressure was 0.02 MPa and the feed concentration was 101.86 g/L, the classification of the cyclone with a better effect.