It can be evaluated in two ways: ① Laboratory water bath：Dissolve and dilute enzyme, and put it in a water bath at a certain temperature for 3 minutes. Compare the activity changes before and after the process to evaluate the thermal stability of enzyme protein. ② Pelleting in the feed factory: Fully mixed Enzyme with feed for pelleting. Then take powder and pelleted feed to test enzyme activity and compare the activity change before and after pelleting.