This study investigated the effect of silica fume(SF) on mechanical properties of concrete incorporating steel slag powder (SSP). The compressive strength and splitting strength tests of concrete with different content of SF (0%, 4%, 8% and 12%) and of SSP (0%, 10%, 20%, 30% and 40%) were carried out, and the test results were analyzed and fitted. Obtained results showed that the brittleness, compressive strength and compressive strength discreteness of concrete increased due to the incorporation of SF. SSP weakened the compressive strength of concrete, which reduced within 10% when the content of SSP was less than 20%. SF and SSP showed synergistic hydration effect when they were mixed, and the optimal group was SF8SSP30, whose compressive strength was close to that of plain concrete, and whose brittleness as well as discreteness of compressive strength were lower relatively. With the content of SSF and of SSP as variables, the tension-compression ratio and compressive strength of concrete can be well estimated by surface fitting.