The stretching of polyolefin are extensively studied, but the situation become quite different when it comes to high-speed industrial processing. Stretch-induced morphological evolutions of quenched polypropylene cast film near commercial line speed are investigated with ultra-fast data acquisition in-situ synchrotron radiation Small Angle X-ray Scattering (SAXS)/Wide Angle X-ray Scattering (WAXS) experiments. The results indicated that strain rate make large difference on the morphological evolution from previous work. Different from low speed stretching, lattices are extensively destroyed upon yielding, but going through weak recrystallization afterwards, even under high temperatures. Fibril crystals are present, however, well-packed large lateral-sized lamellae is not observed. Moreover, a specific deformation model is given to explain the critical points in the stress-strain curve under temperatures from 90 to 150°C. In the beginning, the spherulite overcrowding results in some difference between equatorial and meridional SAXS patterns by the means of intensity and scattering vector distribution. At yielding point the lamellae are broken and lattice take the load. Then the orientation of crystals hardens the whole system. At higher temperatures, the equatorial streaks in SAXS patterns are formed under extremely high strain, indicating the existence of fibrillar crystals. Cavities parallel to the stretching direction are formed right before broken. Through the studies of structural evolution under high temperatures, this work aims to give structural explanations on the origin of phenomena during the processing of biaxially stretching packaging films.