The invention belongs to the technical field of food processing and biological fermentation and provides a method for producing hawthorn vinegar by hawthorn sugary liquor. The method includes steps: diluting the hawthorn sugary liquor with water, adding dried corn pulp powder, ammonium sulfate, magnesium sulfate, biotin, Na2HPO3, CaCl2 and FeSO4 7H2O, and pasteurizing to obtain a fermentation culture liquor; inoculating mixed saccharomycetes into the fermentation culture liquor, culturing at a constant temperature, replenishing the hawthorn sugary liquor until sugar degree reaches 8 Brix, adding sodium glutamate and D-ascorbic acid, inoculating propagated acetobacter aceti AS1.41, using NaOH solution for regulating pH, and fermenting in a constant-temperature shaker; pasteurizing fermentation liquor, cooling, filtering, adding edible salt, ageing at the normal temperature to obtain the hawthorn vinegar. The method solves the problem of resource waste caused by discarding of a large quantity of the sugary liquor generated in a preserved hawthorn processing process. In addition, the method has the advantages of short production cycle, low cost, richness of flavor substances of products and easiness for industrial production.