Abstract: The development of new protein feed is an important means to reduce the cost of feed in the current era when the price of soybean meal is high. Milk thistle meal is a by-product of milk thistle extract silymarin or oil. It has rich nutrients and is a regional protein feed with great potential. Milk thistle meal can be fed directly to domestic animals, but it needs further development because of its poor palatability, low protein content and high crude fiber content. In this paper, the application of milk thistle meal and fermented milk thistle meal in production and the development of their comprehensive properties were reviewed, in order to provide new ideas for the reduction and replacement of soybean meal and the development of new protein feed resources in animal husbandry in China.