The invention discloses a paint which is used for high speed train tunnel draining concealed conduits and is capable of preventing calcium salt deposition, and a preparation method thereof. The paintis capable of alleviating calcium salt deposition in draining concealed conduits greatly, maintaining smoothness of concealed conduit draining, and ensuring high speed train travelling safety, and isprepared through mixing of following raw materials, by weight, 60 to 70 parts of oxysilane, 3 to 5 parts of aminosilane, 2 to 3 parts of alkylphenol ethoxylate dispersant, 2 to 4 parts of cetyltrimethylammonium bromide, and 20 to 31 parts of deionized water. The paint toughness is adjusted with an appropriate amount of acetic acid, and the pH value is adjusted to 4 to 5 based on on-site using conditions.