Abstract: A method for controlling a microstructure of a recycled aluminum alloy includes steps of: degassing and removing inclusions from the molten aluminum alloy, refining grains and controlling the deformed microstructure. Good microstructures of the deformed aluminum alloy can be obtained after degassing by gas flushing, removing the inclusions by filtering, refining the grains by adding a modifier, and extruding or rolling or forging. The present invention provides desirable results of degassing and impurity removal. Contents of hydrogen and inclusions in the refined recycled molten aluminum alloy are 0.02-0.26 ml/100 g Al and 0.4-0.7 area % metallographic field respectively. In an aluminum alloy billet, an average grain size is 25-50 ?m and a short rod-shaped or elliptical second phase is 10-100 nm. In the deformed aluminum alloy, a grain aspect ratio is 10:1-100:1 and short rod-shaped or elliptical particles are 5-80 nm.