Soda residue(SR), slag(S） and fly ash(FA） were taken as main raw materials, with appropriate amount of desulfurized gypsum(DG） and a little compound activator(CA） to prepare a new non clinker incorporating soda residue curing agent. The physical and mechanical performances of the curing agent reach the technical requirements of P·C325 composite cement. New non clinker incorporating soda residue solidified soil and composite cement solidified soil were prepared by adding new non clinker incorporating soda residue curing agent or composite cement(P·C325） into soil with different proportions(by mass）. The engineering properties such as unconfined compressive strength, tensile strength, compression performance, shear performance at 14, 28，90d ages of new non clinker incorporating soda residue solidified soil and composite cement solidified soil were compared. Test results show that the engineering properties of the solidified soil with 20% new non clinker incorporating soda residue curing agent are almost the same as that of the solidified soil with about 10% composite cement.