The invention provides a method for preventing and controlling bioethanol fermentation bacterial contaminationinfection by drug-loading microspheres based on slow and controlled release of drugs and belongs to the field of bacterial contaminationinfection prevention and control in the field of biological energy sources. The method comprises the following steps: preparing 2mg/mL of a chloramphenicol solution by utilizing a citric acid-sodium hydrogen phosphate buffering solution with the pH (Potential of Hydrogen) of 3; putting poly4-vinylpyridine microspheres which are prepared by a suspensionpolymerization method and have the grain diameter of 40 to 100mum into an acidic buffering solution containing chloramphenicol, and sufficiently swelling; washing with ultrapure water, filtering anddrying to obtain the drug-loading microspheres; in an initial fermentation process, adding the sterilized drug-loading microspheres into a fermentation system according to the adding amount of 2mg/mL;culturing under the conditions that the temperature is 30 DEG C and the speed is 150rpm, and carrying out prevention and control on the pollution in a saccharomyces cerevisiae fermentation process. By adopting the method provided by the invention, the product reduction of the bioethanol caused by bacterial infection is successfully inhibited, and the bioethanol yield is improved. the The dosageof antibiotics can be reduced through pH response type release of the drugs in a the fermentation process and the problem caused by antibiotic misuse is alleviated.