Alkali-activated non-sintered ceramsite was prepared with fly ash as raw material and silica fume as supplemented agent. The effect of silica fume content on ceramic properties was systematically studied by means of cylinder compressive strength test, water absorption test, mud content test, abrasion rate test, corrosion resistance test, X-ray diffractometer measurement and scanning electron microscope examination. The results show that at the age of 3 d, 7 d, and 14 d, as the content of silica fume increases, the cylinder compressive strength of fly ash ceramsite gradually increases, while the abrasion rate and water absorption decrease gradually, and the corrosion resistance is also improved. When the silica fume content is 15% and 20% by mass, and the age is 14 d, the cylinder compressive strength of the ceramsite reaches 19.43 MPa and 20.37 MPa. According to the microscopic analysis, appropriate silica fume content increases the hydration degree of fly ash and the compactness of the ceramsite structure, but when the content reaches 15% to 20% by mass, the hydration degree is weakened.