In order to investigate the influence law of polycarboxylate superplasticizer and calcium lignosulfonate as two types of water-reducing agents on the strength of solidified soil,a series of unconfined compressive strength(UCS)tests were carried out for solidified soil with different dosage of water-reducing agents under different curing ages.The evolution mechanism of solidified soil strength with the dosage of two water-reducing agents was described from the perspective of hydration products.The test results show that the strength of solidified soil mixed with two types of water-reducing agents increases with the increase of age,with a fast growth rate in the early stage and a slow rate in the late stage.The strength of solidified soil shows a trend of increasing first and then slowly decreasing with the increase of polycarboxylate superplasticizer content,when the content of polycarboxylate superplasticizer is 0.4%,the strength of solidified soil reaches the maximum value.The strength of solidified soil gradually decreases with the increase of calcium lignosulphonate content.The effect of calcium lignosulphonate on improving strength is weaker than that of polycarboxylate superplasticizer.