In this article, crystalline morphology and molecular orientation of isotactic polypropylene(i PP), random copolymerized polypropylene(co-PP) and ?-nucleating agent(?-NA) composites prepared by pressure vibration injection molding(PVIM) have been investigated via polarized light microscopy, scanning electron microscopy, wide-angle X-ray diffraction and differential scanning calorimetry. Results demonstrated that the interaction between co-PP and i PP molecular chains was beneficial for the mechanical improvement and the introduction of ?-NA further improved the toughness of i PP. In addition, after applying the pressure vibration injection molding(PVIM) technology, the shear layer thickness increased remarkably and the tensile strength improved consequently. Thus, the strength and toughness of i PP/co-PP/?-NA composites prepared by PVIM were simultaneously improved compared to those of the pure i PP prepared by conventional injection molding(CIM): the impact toughness was increased by five times and tensile strength was increased by 9 MPa. This work provided a new method to further enhance the properties of i PP/co-PP composites through dynamic processing strategy. In this article, crystalline morphology and molecular orientation of isotactic polypropylene (i PP), random copolymerized polypropylene (co-PP) and -nucleating agent (? - NA) composites prepared by pressure vibration injection molding light microscopy, scanning electron microscopy, wide-angle X-ray diffraction and differential scanning calorimetry. Results that that interaction between co-PP and i PP molecular chains was beneficial for the mechanical improvement and the introduction of -NA further improved the toughness of i PP. After addition the pressure vibration injection molding (PVIM) technology, the shear layer thickness increased remarkably and the tensile strength improved improved. Thus, the strength and toughness of i PP / co-PP /? - NA composites prepared by PVIM were simultaneously improved compared to those of the pure i PP prepared by conventional injection molding (CIM): the impact toughness was increased by five times and tensile strength increased by 9 MPa. This work provided a new method to further enhance the properties of i PP / co-PP composites through dynamic processing strategy.