Abstract: Taking random copolymerized polypropylene transparent material as an example, the influence of sample preparation parameters on haze of polypropylene transparent material was determined by orthogonal test method, and the best sample preparation parameters were determined. The results show that the main parameters affecting haze were injection pressure, injection speed, mold temperature and melt temperature. The best sample preparation parameters were injection pressure 75 MPa, injection speed 40 mm·s^-1, mold temperature 40 ℃, melt temperature 200 ℃.