Abstract: Taking 7 d unconfined compressive strength as the evaluation index, three ionic soil solidification agents such as YES were used to carry out the solidified soil adaptation test to determine the appropriate mixing ratio of YFS solidified soil. The effects of age, water content, curing method, soaking time and compaction degree on the unconfined compressive strength of YFS solidified soil were studied, and the formation reason of solidified soil strength was revealed by combining with microscopic tests. The results show that the suitable mix ratio of the solidified soil is plain soil and mixed with 0.02% (mass fraction, the same below) YFS curing agent and 5% cement according to its mass ratio; With the increase of age and compactness, the strength of solidified soil increases; With the increase of water content, the strength of solidified soil first increases and then decreases; The room temperature curing strength is slightly lower than the standard curing strength, the strength of the specimen with different standard curing ages decreases slightly with the prolonged water immersion time, and the water stability is good; There is no new material after adding the solidified agent, which can improve the combination mode of soil particles, and the microstructure is mainly composed of aggregates; The hydration product C-S-H gel is formed after cement incorporation,which is filled in the gaps of the aggregates, and makes the overall structure of the soil more compact, and improves the compressive strength of the soil.