The invention relates to the field of sewage treatment, in particular to a treatment method of methanol rectification wastewater in the coal chemical industry. The treatment method comprises steps as follows: coal is primarily broken, coal with the particle size of 150-50 meshes is crude coal powder, and coal with the particle size smaller than 50 meshes is fine coal powder; 59-63 parts of the coal powder, 31-37.5 parts of slurrying water, 5-9 parts of activated sludge and 0.4-0.8 parts of a dispersing agent are weighed in parts by weight, and the mass ratio of the crude coal powder to the fine coal powder is 3:7; the slurrying water, the activated sludge and the dispersing agent are stirred and uniformly mixed, and the molecular structure of the dispersing agent is sufficiently spread; the coal powder is gradually poured into the mixture obtained in the step 2, the stirring rotation speed is increased, and after all the coal powder is added, the mixture continues to be stirred for 20-25 min, and methanol rectification wastewater, sludge and coal slurry is obtained. Organic matters, such as alcohols, a little oil and the like, in the methanol rectification wastewater can generate heat in the gasification process, the organic matters in the wastewater can be sufficiently used, resource utilization of the methanol rectification wastewater is realized, and the treatment problem of the methanol rectification wastewater is fundamentally solved.