In order to improve the utilization of industrial waste residuephosphogypsumblast furnace slag and sodium silicate were conducted to replace part of cement stabilize silt. The regression equation of unconfined compressive strength cured for 3 and 7 d was obtained through the D-optimal mixture designand the optimal mass ratio was calculated. The unconfined compressive strength for 3 and 7 d were separately 4.88 and 5.84 MPa by using the optimal formula to solidified soil samples. The microscopic mechanism of solidified soil was studied by X-ray diffraction and scanning electron microscopy. The results show that the hydration reaction of the optimal solidified soil is more complete than that of the cement solidified soilthe connection between the particles is more denseand the structure is more stable. Finallythe environmental and economic evaluation of the optimal formula was carried outand it is concluded that the formula is superior to cement in strengthenvironment and economy.