In order to further improve the utilization rate of steel slag in steel slag concrete, C30 double-doped steel slag concrete was prepared by replacing natural coarse aggregate and fine aggregate in concrete with coarse steel slag and fine steel slag at the same mass ratio, and the effects of coarse and fine steel slag aggregates substitution level on the mechanical properties and durability of double-doped steel slag concrete were studied. The results show that the mechanical properties of double-doped steel slag concrete are generally better than those of ordinary concrete. With the increase of coarse and fine steel slag substitution levels, its mechanical properties are enhanced, its carbonization resistance is first enhanced and then weakened, and its resistance to chloride ion permeation is gradually weakened. In this paper, the relationship between the cubic compressive strength of double-doped steel slag concrete and other mechanical indexes was also studied, and the corresponding conversion formula was given. Considering both the mechanical properties and durability of double-doped steel slag concrete, it is suggested that the replacement rate of coarse and fine steel slag aggregates should not be higher than 40% （mass fraction）.