The invention discloses a cooling liquid for cutting a solar silicon wafer through a diamond wire. The cooling liquid consists of the following raw materials in parts by weight: 2-3 parts of triethanolamine, 2-4 parts of glycerin, 2-3 parts of methoxy polyethylene glycol, 3-5 parts of hydroxyethyl acrylate, 2-3 parts of fatty alcohol-polyoxyethylene ether, 3-4 parts of p-toluenesulfonic acid, 2-5 parts of fumaric acid, 1-2 parts of phthalic anhydride, 2-4 parts of maleinimide, 1-3 parts of cis-butenedioic acid, 2-4 parts of diisopropanolamine, 2-3 parts of n-butylamine, 1-2 parts of tri-isopropanolamine, 2-3 parts of potassium sorbate, 1-3 parts of phenoxyethanol, 2-3 parts of methylparaben, 2-3 parts of ethylenediamine tetraacetic acid, 2-5 parts of titanium dioxide, 2-4 parts of methyl methacrylate, 3-5 parts of acetone, and 50-70 parts of deionized water. The cooling liquid for cutting the solar silicon wafer through the diamond wire can be well applied to cutting with the diamond wire, is good in lubrication and cooling effects, low in cost and free of pollution, can effectively reduce the breakage rate, has a good dispersion function on silicon powder and iron impurities generated in the cutting process, and ensures the surface property of the silicon wafer.