Ball milling and mixing with strong shear force and strike force were applied to get fine dispersion of nano-SiOx, particles in poly(phenylene sulfide) (PPS) powder. Nano-SiOx/PPS composites were manufactured by intensive compounding with 3 wt% nano-SiOx particles. Effects of the ball milling dispersion on crystal behavior and impact strength of nano-SiOx/PPS nanocomposites were studied. Physical mechanisms of ball milling dispersion were investigated. Evaluations based on both WAXD and DSC indicates that crystallization behavior of nano-SiOx/ heat-treated PPS (HT-PPS) nanocomposites was influenced by the ball milling process. Their crystallinity was 25% less while Izod impact strength was 89% better than those of as-received neat PPS. Increased kinetic energy via ball milling by external work makes nano-SiOx able to overcome the attraction from itself to prevent agglomeration. Interfacial bonding of two phases between nano-SiOx and PPS was enhanced by crosslinking in HT-PPS and reduction in surface tension of interface during ball milling. The bonds allow SiOx to dissipate energy and thus improve PPS impact strength from the addition of nano-SiOx.