The invention relates to a binder, in particular to an inorganic phenolic aldehyde composite binder capable of improving the sand regeneration rate. Comprising the following components in percentage by weight: 10%-30% of sodium silicate, 10%-25% of a phenolic compound, 25%-40% of formaldehyde, 0.1%-0.3% of a metal chloride modifier, 0.1%-0.2% of a reinforcing agent, 3.2%-19% of water, 0.1%-0.3% of a nonionic surfactant, 0.2%-0.4% of a sodium hydroxide solution and 15%-20% of a potassium hydroxide solution. The binder disclosed by the invention has the characteristics of high sand regeneration rate, high strength, normal-temperature hardening and environment friendliness, and the sand regeneration rate of a traditional inorganic binder is increased from about 80% to 97.1%; on the basis, the bonding strength of a traditional inorganic binder is improved by about 25%; the defects of single phenolic resin in the aspect of environmental protection are reduced; and normal-temperature hardening can be carried out under the condition of adding a curing agent.