The invention provides a rust-proof corrosion inhibitor and the preparing method thereof. The rust-proof corrosion inhibitor comprises sodium silicate, sodium polyacrylate, mercaptobenzothiazole, benzotriazole, sodium tripolyphosphate, hexamethylenetetramine, imidazoline, mercaptobenzothiazole, alkane amido alcohol, furfural, polyphosphates, ethanol amine, sodium borate and ethyl alcohol. The preparing method comprises the steps of heating sodium silicate, sodium polyacrylate, mercaptobenzothiazole, benzotriazole, sodium tripolyphosphate, hexamethylenetetramine, imidazoline, mercaptobenzothiazole, alkane amido alcohol, furfural, ethanol amine and ethyl alcohol mixed liquor to 50-60 DEG C firstly, then adding polyphosphates and sodium borate, continuing to heating to 85-90 DEG C, conducting heat preservation for 2-3 h, and then obtaining the rust-proof corrosion inhibitor after cooling. The rust-proof corrosion inhibitor can be well compatible with variable materials, rust-proof time is long and can be as long as 4-6 months, adaptability to the copper material and the aluminum material is high, and rust-proof time is prolonged due to the fact that a film can be formed on the surface of metal while corrosion inhibition and rust resistance are realized.