Pulse aeration device, membrane bioreactor and membrane flushing method

The pulse aeration device comprises a gas chamber, an inner pipe, an outer pipe, a gas supply pipe and a fixing piece, the gas chamber is a container with an open lower part and is used for accumulating and temporarily storing gas from a gas source; the air supply pipe is connected with an air source outside the air chamber and used for supplying air to the air chamber. The upper part of the outer pipe is higher than the outer wall of the top of the air chamber by a certain distance, the lower part of the outer pipe is a certain distance from the bottom of the air chamber, and the outer pipe is a channel for releasing air in the air chamber to the outside; the positions of the inner pipe and the outer pipe are fixed through a component, the upper portion of the inner pipe is open, the upper portion of the inner pipe is open and located in the air chamber, the bottom of the inner pipe is communicated with the bottom of the outer pipe, the structure of the outer pipe and the inner pipe is equivalent to that a p