ABSTRACT Silica serves as a primary filler in the tread rubber of green tires. In theory, the wet skid resistance of tread rubber increases with higher silica content, thus promoting driving safety. But the trend of silica agglomeration becomes serious with increasing silica content. Addressing silica agglomeration is critical for developing high‐performance tread rubber. In this article, the effect of silica content on the various performance of two kinds of solution‐polymerized styrene butadiene rubber (SSBR) filled with 80 to 120 phr silica is studied. With increasing silica content, the water contact angle of vulcanized SSBR decreases, and the wet friction coefficient increases, indicating the improvement of wet skid resistance. Despite the fact that the wet skid resistance of highly filled silica/SSBR composites improves, other properties such as abrasion resistance performance and dynamic mechanical properties become worse, which is related to the serious agglomeration of silica. The wet friction coefficient of highly filled silica/SSBR composites has a close relation to the wet skid resistance, but they do not have a positive correlation with the tan δ values at 0°C. This study has a reference value for the development of highly filled silica/SSBR composites used for tread rubber of green tires.