A project in Dalian intends to use dredged silt as filling resources after solidification treatment.It is necessary to obtain the optimum solidifying agent types and mix proportion to meet the strength requirements of engineering filling soil by means of experiments.There are too many factors affecting the strength of solidified soil,thus,the rough set theory is used to analyze the influences of water-solid ratio,curing agent dosage,curing agent type and external admixture on the strength so as to explore the most significant impact indicators.The results show that:1）In order to ensure that the strength of the solidified soil meets the requirements of the project fill soil,the research work should be carried out with the curing agent type and curing agent dosage as variables to explore the most economical curing agent preparation plan. 2）In practical application,no admixture can be added to save cost.3）In a certain range,the water-solid ratio can be properly increased to meet the transportation requirements.