The invention discloses aluminum alloy hard anodizing electrolysis and a maintenance method. According to the electrolyte, additives containing molybdenate, phosphas phosphate and tellurate are added into sulfuric acid/oxalic acid mixed acid solutions, and aluminum alloy part as an anode is immersed into the electrolyte, positive direct current pulse current is applied for anodizing electrolysis; the aluminum alloy part does a reciprocating translation motion in an electrolysis process, and a freezing pipe is assisted to be cooled so as to ensure that air inflating stirring and stirring of an overflow tank pump of the electrolyte at a temperature of 20 DEG C or below in an electrolysis process; after each 100 liters of electrolyte is electrified to 20000AH, 5 to 10ml/L additive solutions are needed to be supplemented and are filtered by a filter pump. An aluminum alloy hard oxide film obtained by the electrolyte disclosed by the invention has higher thickness and hardness, moreover, the burning loss of an oxidized layer is avoided, and the phenomenon that the consistency of the quality of the oxide film is kept due to the stable operation of the electrolyte can be ensured.