Abstract: Controlled low-strength materials(CLSM) were prepared with red mud,fly ash and mineral powder as raw materials,NaOH as activator and polycarboxylate superplasticizer as dispersant. The working and mechanical properties of the materials under different mixture ratios of red mud and fly ash were studied. When the dosage of red mud and fly ash is 2 ∶1,the dosage of mineral powder is 10% and the dosage of NaOH is 1. 5%,the maximum fluidity of mixing flow is 236 mm,and the maximum unconfined compressive strength of the specimen at 28 days is 6. 5 MPa,which meets the specification requirements of controlled low-strength materials. XRD,FTIR and SEM were used to explore the mineral composition and microstructure of controlled low-strength materials. It was found that red mud,fly ash and mineral powder were hydrated to form C—S—H,AFt, a small amount of hydrated calcium pyrite and C₄AF. The strength development of materials depends on the microstructure of flocculent,honeycomb and sheet. The research results provide a new technical way for the large-scale application of industrial solid waste in the field of controlled low-strength materials.