[Objective] To analyze the effects of dietary supplementation with dandelion extract on the growth performance,lactation performance and immune indicators of dairy cows. [Method] A total of 160 dairy cows with similar body weight and parity were selected as the research objects in a large-scale dairy farm in Shan County. They were randomly divided into 4 groups by the random number table method,with 5 replicates in each group and 8 cows in each replicate. They were the control group,the low-dose group,the medium-dose group and the high-dose group respectively. The control group was fed with the basal diet,while the low-dose group,medium-dose group and high-dose group were respectively supplemented with 0.2%,0.4% and 0.6% dandelion extract on the basis of feeding the basal diet. The experimental period was 50 days. After the experiment,the growth performance,lactation performance and immune indicators of each group were analyzed. [Result] The average daily feed intake and average daily weight gain of dairy cows in the low-dose group,medium-dose group and high-dose group were significantly higher than those in the control group（P< 0.05）,and the feed conversion ratio of dairy cows in the medium-dose group was significantly lower than that in the control group（P< 0.05）. The indicators of milk production、milk protein rate、lactose rate of dairy cows in the low-dose group,medium-dose group and high-dose group were significantly higher than those in the control group（P< 0.05）,while the indicators of somatic cell number and milk urea nitrogen were significantly lower than those in the control group（P< 0.05）. The contents of IgM,IgG and IL-10 in dairy cows in the low-dose group,medium-dose group and high-dose group were significantly higher than those in the control group（P< 0.05）,and TNF-α was significantly lower than that in the control group（P< 0.05）. [Conclusion] Under the conditions of this experiment, the optimal dosage of dandelion extract in the diet was determined to be 0.4%. Dietary supplementation with dandelion extract can promote the growth of dairy cows, improve lactation performance,and enhance immune function,providing a scientific basis for the rational use of natural additives in dairy farming.