Water-based acrylic acid paint utilizing negative ions to purify air is disclosed. 1-5% by weight of a negative ion paint additive is added into water-based acrylic acid paint. The additive is prepared by modifying negative ion powder and activated carbon powder with a titanate coupling agent. According to the provided water-based acrylic acid paint utilizing the negative ions to purify air, the titanate coupling agent is adopted to modify tourmaline in the negative ion powder and the negative ion powder is composited with the activated carbon powder, and therefore surface hydrophobicity of the tourmaline is improved, the crystal structure of the tourmaline is not destroyed, original physical characteristics of the tourmaline are not influenced, and negative ion release of the tourmaline is improved than negative ion release of tourmaline treated with a traditional silane coupling agent, thus improving air quality.