64 kinds of volatile organic compounds(VOCs) of EPA TO-15 as the foundation, out of which 7 kinds of toxic substances lower than the toxicity of ethanol, while adding 27 kinds of toxic substances than the toxicity of ethanol, the volatile organic toxic pollutants (VOTCs) lists were established. The equivalent weighted toxicity evaluation method was used to evaluate the comprehensive biological toxicity of volatile organic compounds in air and waste gas. The results show that the comprehensive toxicity of volatile organic toxicant could well reflect the comprehensive toxicity of VOCs. When there are kinds of pollutants in the waste gas or environmental air, the comprehensive toxicity is far higher than the single pollutant's toxicity and the evaluation result is more close to the actual pollution level of the waste gas.