For the direct use of high-liquid-limit clay fill roadbed may have different degrees of disease due to insufficient strength and stability, Taking the high liquid limit clay distributed in the Dongting Lake area as the object of study, By mixing the recycled powder of waste concrete prepared in the laboratory, Conduct experimental research on high liquid limit clay improvement, The dosing amounts are set at 5%, 10% and 15%, respectively,The regimen cycles were 7d, 14d, 28d and 90d, respectively. The variation of liquid-plastic limit, CBR bearing ratio and unconfined compressive strength were studied, and compared with 3% cement amended soil. The test results show that the improvement of high liquid limit soil with 10% admixture of recycled powder and 14d regeneration period has significant strength enhancement effect.