Abstract: Aiming at the problems in the preparation of cement solidification of intermediate and low level radioactive liquid waste with complex components in a nuclear power plant, such as rapid fluidity loss, bleeding and laminate, difficult control of setting time, etc, the effects of admixtures, water retaining and thickening materials and feeding sequence on the fluidity, water retaining performance, setting time and properties of radioactive liquid waste cement solidification were studied. A special additive and formula for radioactive liquid waste cement solidification have been developed, which not only meets the national standard GB 14569.1-2011, but also applies to existing engineering units. The special additive includes fly ash, thickening powder and admixture A in the mass ratio of 1∶1∶0.15, and the formula of cement solidification includes cement, special additives and liquid waste in the mass ratio of 1∶0.272∶0.585.