Abstract: To promote the environmentally friendly development of construction materials such as concrete and the resource utilization of industrial solid wastes, an all-solid-waste, low-carbon concrete based on a silica fume-coal fly ash-blast furnace slag-iron tailings system was developed. A systematic study was conducted on the effects of different silica fume contents on the slump flow, setting time, compressive strength, chloride ion concentration, and freeze-thaw cycle resistance of the concrete, and the hydration mechanism was further investigated in depth. The results indicated that as the silica fume content increased, both the spreading of the concrete paste and the initial/final setting times exhibited a decreasing trend. At a silica fume content of 15%, SC3 achieved its maximum compressive strengths at 3 days, 7 days and 28 days, which were 8.70, 15.89 and 32.89 MPa, respectively. The chloride concentrations in the extracts from KC1, KC5 and SC3 after 3, 7 and 28 days of hydration were below 0.12 mg/L, significantly lower than the 250 mg/L limit specified in Standards for Drinking Water Quality (GB 5749-2022). Under identical freeze-thaw cycle conditions, the addition of 15% silica fume reduced the concrete's mass loss rate, compressive strength loss rate, and relative elastic modulus loss rate in the SC3 test. Moreover, the relative elastic modulus and compressive strength loss rate exhibited a linear negative correlation (R²=0.90), demonstrating that higher compressive strength and structural rigidity in concrete were conducive to enhancing its resistance to freeze-thaw cycles. The hydration mechanism indicated that adding an appropriate amount (15%) of silica fume enhanced the hydration reaction process of SC3, promoting the crystallization of hydration products such as C—S—H gel, calcium aluminate hydrate, Kuzel salt, and Friedel salt. The aforementioned products could be filled into the pores of concrete to enhance the structural compactness.