Multi-level multi-phase flow aeration mixing device

The utility model discloses a multi-level multi-phase flow aeration mixing device which comprises a submersible sewage pump, wherein the submersible sewage pump is connected with a main pipe; at least one pipeline pump is arranged on the main pipe; multiple water ejectors are arranged on the main pipe; the water ejectors are connected with an air inlet pipe or a sewage inlet pipe alternately from top to bottom; the lower end of the main pipe is close to the bottom of a biological reaction area; a diffusion port is formed at the lower end of the main pipe; the water ejector is of an ejector structure; a branch pipe of the ejector is connected with the air inlet pipe or the sewage inlet pipe. In the multi-level multi-phase flow aeration mixing device disclosed by the utility model, by adopting a mode of multi-level jet flow and alternate mixing of air and sewage, bubbles are smaller, and the contact area between gas and sewage is larger. The contact time between the air and microorganisms in the sewage is prolo