This paper reports a simple, high-efficiency, and green approach for preparing high-dispersion silica-g-solution styrene butadiene rubber (SiO2-g-SSBR) through a solution mechanochemical reaction in a laboratory planetary ball mill. The condensation reaction between the hydroxyl groups on the silica surface and the siloxane groups of SSBR-g-3-mercaptopropyltriethoxysilane (MPTES) was verified. The results revealed that the chemical modifications of silica through an SSBR polymer matrix weakened the strong filler filler interactions and enhanced the weak filler polymer interfacial interactions simultaneously. Because of the dual role of SSBR-g-MPTES as a dispersant and rubber matrix, the modified silica showed high dispersion in the SSBR composites regardless of the compounding, storage, or vulcanization period. Additionally, the dispersion of modified silica was superior to that of silica modified through bis(gamma-triethoxysilylpropyl)-tetrasulfide (Si-69). Compared with the unmodified silica/SSBR composite, the performance of the composites was obviously improved, the rolling resistance decreased by 28.4%, wet skid resistance increased by 63.9%, and tensile strength increased by 40.4%.