Influenced by different dry-wet cycles combined with acidic environment， lime-metakaolin（L-MK） and natural hydraulic lime（NHL） modified site soils were tested for unconfined compressive strength and split tensile strength， and color difference analysis was carried out on the basis of color consistency. X-ray diffraction（XRD）， thermo gravity（TG） and scanning electron microscopy（SEM） tests were used to explain the strength degradation mechanism. The results show that the strength of L-MK modified site soil increases first and then decreases with the increasing number of dry-wet cycles in acidic environment， while the strength of NHL modified site soil decreases monotonically. After 20 dry-wet cycles in acidic environment， the strength of L-MK modified site soil is more than 1.6 times that of NHL modified site soil. Comparing the color parameters of the earthen site soil， the color difference of the L-MK modified site soil （with MK content of 8%） is less than that of the NHL modified site soil. The variation of strength is depended on the stability of hydration product calcium silicate hydrate （CSH） and the amount of expansive material such as CaSO₄·2H₂O produced. It is feasible to use L-MK instead of NHL in the field of site soil restoration.