Abstract: Starting from improving efficiency of small and medium-sized breeding farms and saving labor, feed mixing process was improved．A feed mixer was developed using engineering design principles．After determining total design concept and working principle, final assembly design and key component design were carried out．Applicability of feed mixer was verified through experiments．When mixing time was 100 s, coefficient of variation（CV）of mixture uniformity was 7%．Successful development of feed mixer could improve economic benefits of small and medium-sized breeding farms and has certain significance for promoting modernization of agricultural development．