Abstract Dry granulation, as a new process for molten blast furnace slag treatment, is an attractive alternative to water quenching. In this study, the performance of dry granulation slag in slag cement blends was investigated. The results demonstrated that the early strength for dry granulation slag cement mortar was too low, which is less than 50% of the strength for the cement clinker. After 28 days, the compressive strength for dry granulation slag cement mortar containing 35 min-milled slag powder was higher than that for cement clinker. With a decrease in cement/slag ratio, the compressive strength for dry granulation slag cement mortar decreased, and then increased, reaching 96.4% of the compressive strength for dry granulation slag cement mortar made with cement/slag ratio of 2:1. Although the content of cement clinker decreased, there was enough Ca(OH)2 to activate dry granulation slag particles to form compact C S H structure when the cement/slag ratio was 1.5:1.