The invention discloses a method for preparing an industrial sodium silicate adhesive. The method comprises the following steps of firstly preparing a sodium orthosilicate crude product, preparing solid sodium silicate, dissolving the solid sodium silicate into a special mixed solution of an adhesive and water, and then filtering to obtain a sodium silicate solution; adding sodium hydrogen sulfite to the sodium silicate solution to generate precipitated light silicon dioxide and a sodium sulfite solution, and filtering the generated mixture; concentrating and drying the other part of filtrate to obtain high-quality industrial sodium silicate; and mixing the prepared high-quality industrial sodium silicate and 2-fold resin emulsion, adding the mixed solution to silica sand, and fully mixing to obtain the sodium silicate adhesive. Main ingredients of the sodium silicate after being hardened are a silicon gel and a solid, the specific surface area is large, and the adhesive property is greatly improved. The sodium silicate is treated by using the special mixed solution of the adhesive and water with moderate concentration, so that the water resistance is improved, and the sodium silicate adhesive is very convenient to transport, store and use, and is especially suitable for mechanized and automated operation.