The invention provides a milk processing factory wastewater treatment method. The treatment method includes the steps that wastewater passes through a flow and water quality regulation stage, an anaerobic hydrolysis acidification stage and a contact oxidation stage in sequence to be treated; after scum and settling sludge separated and gathered from the wastewater in the anaerobic hydrolysis acidification stage are broken, the wastewater flows back into the anaerobic hydrolysis acidification stage to be treated; after scum and settling sludge generated in the hydrolysis acidification process are gathered through a scum (sludge) scraping machine and mechanically broken, the wastewater flows back to the anaerobic hydrolysis acidification stage to be treated; thus, the purposes of low-cost treatment (the cost is reduced by 30% or above) of the milk processing wastewater and zero discharge of organic sludge are achieved. By means of the treatment method, after 1.5-4 days of retention time, raw water with the content of suspended solids being 300-1200 mg/L, the content of dissolved organic matter being 1000-5000 mg/L and the content of NH+ being 5-60 mg/L can meet the effluent class-IV standard without generating excess sludge, and the problems of high flocculant cost, high air flotation energy consumption, high sludge treatment expenses and the like in the wastewater treatment process are solved.