The dry shrinkage and freeze-thaw cycle tests were conducted to discover the response characteristics of steel slag mixed soil base material under environmental conditions, the dry shrinkage strain, water loss rate, dry shrinkage coefficient, freeze-thaw mass loss rate and BDR were used as indicators, respectively. It is found that the 28 d dry shrinkage coefficient and freeze-thaw mass loss rate decrease, and BDR increases first and then decreases with the increase of steel slag proportion. It exhibits peak value of 96.1% when steel slag proportion is 50% (mass fraction), indicating that the appropriate steel slag proportion could not only restrain the dry shrinkage of steel slag mixed soil, but also endow it with better frost resistance. With the increase of cement dosage, the 28 d dry shrinkage coefficient and BDR increase, and the freeze-thaw mass loss rate decreases, which indicates that the increase of cement dosage is harmful to the dry shrinkage performance of steel slag mixed soil but is beneficial to its frost resistance. It is also found that soil curing agent can improve the drying shrinkage performance and frost resistance of steel slag mixed soil. SEM investigation implied that the steel slag mixed soil with 50% steel slag proportion and 5% cement dosage exhibits a closer structure and better integrity after 8 freeze-thaw cycles. By comparing the drying shrinkage coefficient and BDR of different base materials, it is found that the dry shrinkage performance of steel slag mixed soil is inferior to that of cement stabilized macadam, but is superior to that of cement lime stabilized soil, and the frost resistance reaches or even exceeds cement stabilized macadam.