The invention discloses a colorant for improving softness of hog bristles. The colorant includes: natural dye, quinoline yellow, rare earths, nano SiO2, aluminum ammonium sulfate, sodium sulfate, sodium hydroxide, potassium sorbate, chitosan, a penetrant JFC, polyvinyl alcohol, propylene glycol, alkyl glycoside, sorbitol anhydride trioleate, dinaphthyl sodium methanedisulfonate, a dispersant WA, chalcanthite, dibutyl sebacate, epoxidized soybean oil, epoxy rice bran oleic acid butyl ester, ethyl benzoate, a softener YS, a softener ES, and deionized water. The colorant is low in pollution and is high in dyeing efficiency and can form deep and uniform color. The dyed hog bristles have good light resistance and weather resistance, are not liable to discolor, have good color fastness and are improved in elasticity and softness. The colorant effectively improves performance and prolongs service life of hot bristle products.