The 3U chain block (USO) is used to link the rich and the currency exchanges. The 3UDAO of the 3U block chain is a distributed autonomous organization based on the Axi chain. Anyone can join the partner. The value of the 3U block chain is mainly embodied in the community construction and ecological development, and provides technical training, 3U rating, project hatching and investment fund for the partners of 3UDAO.