The invention provides a plasticity-maintaining stabilizer used for a cement-based binding material. The plasticity-maintaining stabilizer is a water solution of a solid-liquid/solid-solid composition, the total mass of the solid-liquid/solid-solid composition is 100 parts, and the solid-liquid/solid-solid composition is prepared from the following raw materials of components in parts by weight: 5 to 15 parts of a plasticity expanding agent, 10 to 25 parts of a foam stabilizer, 5 to 10 parts of a soap air-entraining agent, 35 to 40 parts of a metal soap lubricating agent and 35 to 45 parts of a plasticification degree SD balancing agent. The mixing amount of the plasticity-maintaining stabilizer in the cement-based binding material accounts for 0.1% to 0.3% of the total mass of the binding material. The plasticification degree SD value is adjusted by adopting the plasticification degree SD balancing agent in the component design of the plasticity-maintaining stabilizer, and the influences of overcuring on mobility and slump loss resistance of the cement-based binding material mixture are fundamentally solved; and different from a solution of adding a retarder and a water reducer, the plasticity-maintaining stabilizer completely eradicates the defects such as mixture segregation and bleeding or too long delayed coagulation time caused by excess additives.