Abstract: Computational Fluid Dynamics （CFD） was used to analyze the flow field in the first reactor of a polypropylene plant. Firstly, a CFD software, FLUENT, was used to simulate and analyze the influence of the turbine type agitator with folded blades and the turbine type agitator with folded blades on the flow field distribution inside the agitator. Use standard k- ε The turbulence model simulates the flow field of the stirred solution in 3D, and the simulation study shows that the inclined blade disc turbine stirring impeller flows more fully in the reactor and has a better stirring effect on the material. The second simulation was conducted on the different pitch distances of the first three rows of folded disc turbine type stirring paddles, and it was found that the best mixing effect was achieved when the pitch distance D=1.0D₀ （diameter of stirring paddles）; Finally, the flow field distribution inside the reactor was analyzed and simulated under different blade angles. Obtained the optimal folding blade tilt angle.