Step：

1. Soak the dried deer sinew for 2 days and blanch it in water until soft;
2. Cut Astragali Slice and Pilosulae into slices and rinse them together with Ningxia Fructus thoroughly;
3. Soak Yam Slice for 1 hour and rinse it thoroughly;
4. Defrost the crocodile backbone and blanch it with pork bone for later use;
5. Put all ingredients into a casserole, pour in some hot water, and bring it to the boil, then reduce to a simmer over medium heat for about 2.5 hours, add salt before serving.