Abstract: Using guava-like polyacrylate-3-(methacryloyloxy) propyltrimethoxysilane modified silica (PAcr MPS-SiO₂) grafted composite particles as the dispersion phase, and polymethylmethacrylate (PMMA) resin as the continuous phase, their mixture was melt blended in a HAKKA torque rheometer, in order to investigate the dispersion and orientation behavior of the grafted composite particles with different crosslinking structures under various melt shear conditions. It is found that due to the induced effect provided by the strong shear force in the melt-mixed field, and also the restraint effect provided by the widespread grafting cross-linking structure formed with SiO₂ particles as the cross-linking point and the grafted polymer chain as the linking line in PAcr-MPS-SiO₂ particles, the guava-like composite particles are likely to be oriented and rearranged. They can be in turn deformed into sphere, ellipsoid, rod-shaped, microfibril and other oriented morphologies without large-scale tear dissociation, and finally in-situ formed a fibrous orientation structure with a large aspect ratio in the polymer matrix. The degree of orientation of the composite particles and the grafted SiO₂ clusters inside could both be controlled within a certain range, by adjusting the degree of crosslinking of the PAcr-MPS-SiO₂ composite particles from changing the degree of MPS modification on the silica surface, or by adjusting the shear strength of the melt shear field from changing the screw speed. When the gel fraction of the composite particles is 40%, the mixture temperature is 180℃, the screw speed fixed at 65 r/min and the blending time of 12 minutes, an ordered alongside oriented structure with an average aspect ratio of 11.8 can be obtained. Accordingly, we would believe this study could open a new pathway to in-situ construct and effiviently regulate one-dimensional orientation structure in polymer matrix.