With the increasing demand for beef and milk products,the scale of China's cattle industry has gradually increased,and the ruminant feed market has developed rapidly. From the annual national feed quality and safety monitoring results,the overall qualified rate of domestic feed products exceeds 90%. However,in the process of dairy farming,individual free range farmers will feed dairy cows with by-products in agricultural production in order to reduce costs. If the processing or feeding methods are improper,dairy cows will be poisoned and the safety of dairy products will be threatened. From the perspective of agricultural and sideline products commonly used in its production,they mainly include corn,potato,cottonseed cake, Chinese cabbage,radish and sweet potato. However,due to incorrect picking time, unreasonable storage conditions and no inspection before feeding,dairy cows will damage rumen and the health of the whole body due to eating deteriorated feed. Because this feed borne poisoning often causes acute symptoms,if the breeding personnel are not experienced or improper daily care,it will cause the death of dairy cows and seriously affect the breeding efficiency. In view of this,this paper summarized the poisoning symptoms,treatment methods and preventive measures of common feed for dairy cows,in order to improve the safety of feed for dairy cows and promote the healthy development of dairy farming in China.