The polypropylene (PP) was modified by β-nucleating agent to prepare PP masterbatch with the β-nucleating mass fraction of 5%. The PP masterbatches are then injection molded with PP in various ratios to form PP standard test specimens, which are subsequently subjected to mechanical property testing. The results showed that the β-nucleating agent had a significant toughening effect on the homopolymer PP 1100N. When the mass fraction of β-nucleating agent is 0.02%, the notched impact strength at room temperature increases from 5.0 kJ/m² to 9.1 kJ/m², with an increase of 82%. At a mass fraction of 0.15%, the notched impact strength at room temperature reaches its maximum, increasing from the original 5.0 kJ/m² to 11.5 kJ/m², with an increase of 130%. The low-temperature impact strength also increases with the addition of β-nucleating agents, from 2.0 kJ/m² to 2.6 kJ/m², with an increase of 30%. The incorporation of β-nucleating agents affects the tensile properties of the material. At a mass fraction of 0.05% of β-nucleating agent, the tensile strength reaches a maximum of 30.98 MPa, which is a 13.27% increase in tensile strength compared to the blank sample without addition, and the elongation at break also increases from 708.95% to over 1 060.00%. The addition of β-nucleating agents affects the bending properties of the material and reduces its rigidity, but the impact is not significant.