Abstract: On the same blank mix proportion, steel fiber of 0～1.2 %( by volume content) and 0～12% of silica fume (replace cement by quality) are mixed into concrete. And the compressive strength, bending strength, slitting strength of concrete at the age of 28d by standard curing are tested. At the same time, the pore structure characteristics parameters of concrete are tested by nitrogen adsorption experiment. The result of this paper show that, the compressive strength, bending strength, slitting strength of steel fiber reinforced concrete are increased as the adding of silica fume, and the strength increased significantly with increasing replacement of silica fume. The quantitative relation between 28d flexural strength and the content of steel fiber and silica fume are established, and the impact trend of silica fume and steel fiber on the flexural strength of concrete 28d is predicted.