Submersible mixer convenient to maintain

The utility model relates to a submersible mixer convenient to maintain, which comprises a base, a vertical guide rail and a support are respectively fixed at the upper end of the base, the base is placed at the bottom of an AAO (anaerobic-anoxic-oxic) biological tank, the upper end of the guide rail extends to the upper end of the AAO biological tank, the upper end of the guide rail is fixed with the shore of the AAO biological tank, and the lower end of the guide rail is fixed with the shore of the AAO biological tank. A stirrer support which is transversely arranged is connected to the guide rail in a sliding mode, a stirring paddle which rotates vertically is arranged at the front end of the stirrer support, and the support abuts against the bottom end of the stirrer support. The submersible stirrer disclosed by the utility model can be maintained and overhauled without draining water, so that the operation problem that the production can not be stopped or the water tank can not be emptied for maintenance