Abstract: Geopolymer cementitious materials can replace cement-based cementitious materials as curing agents in engineering problems, such as backfilling of narrow fertilizer troughs, and effectively reduce pollution and energy consumption in the cement production process. There are few studies on cementitious materials. Three new green cementitious materials combined with alkali activators are used to solidify engineering slag and form fluidized geopolymer-solidified soil. The strength prediction model is established to analyze the influence of different factors on the strength. The results show that the strength of the solidified soil increases first and then decreases with the increasing modulus of the alkali activator, increases with the content of GGBS, fly ash and rice husk ash, and decreases with the increasing particle size. When the modulus of alkali activator increases to 1.2, the content of GGBS increases to 10%, the content of fly ash increases to 8%, and the content of rice husk ash increases to 11%, the strength of the solidified soil increases significantly. The average relative error of the prediction results of the strength prediction model is only 5.57%, which is relatively accurate for the solidified soil. The calculation results of the weights of each layer in the prediction model show that the curing age has the greatest impact on the strength of the solidified soil, and the particle size of rice husk ash has the minimal impact. The research results can provide theoretical support for the application of solidified soil in practical engineering.