In order to overcome the low strength and high deformation characteristics of Shanghai clay, this paper studied that mixed construction waste fines and lime powder into Shanghai clay with different weight reinforcement ratios, and cured the clay with different amounts of time. Through unconfined compressive strength testing, we investigated the impact of construction waste fines and lime powder on the compressive strength of Shanghai clay. The results indicated that construction waste fines had no obvious impact on soil compressive strength, but improved the ductility of soil. The lime powder can effectively improve the compressive strength of Shanghai clay as well as soil residual strength. The compressive strength and ductility of the soil is enhanced and its brittleness is reduced when construction waste fines and lime powder are mixed into the clay. The most suitable reinforcement ratio for compressive strength of soil is 20% of construction waste fines and 4% of lime powder.