To investigate the mechanical properties of the lime-treated expansive clay，the experimental analysis of compressive properties，unconfined compressive strength and shear strength was performed on he lime-treated expansive clay with different lime content and curing time. The study showed that the compression coefficient of lime-modified expansive soil showed a trend of increasing first and stabilizing eventually with the increase of lime dosing and curing time. The change of unconfined compressive strength of improved expansive soil increases exponentially with the increase of lime content.When the samples were cured for 1 d，the lime content is 2%，4%，6% and 8%，the unconfined compressive strength increases to 311.9，206.9，177.8 and104.8 kPa，respectively.Both the cohesion and internal friction angle of the modified expansive soil increase rapidly wiithin the curing period. Those increases exponentially at early stage of curing. However，the growth rate slows down with the increase of curing time，as the lime gradually flocculates，causing the content of produced flocculation product to stop increasing.The results can provide reference for the engineering application of limeimproved expansive soil.