Preserved eggs are processed from Weishan Lake duck eggs, which are nutritious and delicious, and have the effects of helping digestion, appetizing and benefiting the heart. After shelling, the egg body is complete and has become reddish brown or greenish brown and transparent. There is a complete image of pine branches and leaves on the surface, which is very beautiful. This is also the origin of the name of preserved egg. Egg yolk has a colorful sugar heart, which accounts for one third of the whole egg yolk.