The invention relates to the technical field of a cleaning agent, in particular to a nonaqueous cleaning agent. The nonaqueous cleaning agent is prepared by mixing the following raw materials in percentage by weight: 60 to 80 percent of fusel oil, 10 to 18 percent of fusel alcohol ester, 6 to 12 percent of glyceryl monooleate, 3 to 8 percent of citric acid and 4 to 8 percent of cholamine. The nonaqueous cleaning agent does not contain water or metal ions; meanwhile, under the joint effects of various alcohols and mixed esters, glyceride, citric acid and cholamine, good seepage, wetting and dissolution effects are achieved on the surface of a substance to be cleaned, particularly the surface of metal; various kinds of oily contaminants can be effectively cleared. The coal-to-methanol byproducts of fusel oil are used as main ingredients; other auxiliary agents are added and mixed; the cleaning agent is prepared. The cleaning agent provided by the invention has the advantages that the rawmaterials can be easily obtained; the price is low; the cleaning effect is good; more importantly, a method is provided for the reasonable and comprehensive application of resources.