The invention discloses a high-plasticity high-strength cast aluminum alloy containing barium and cerium and a manufacture method thereof. The alloy contains the following ingredients (by weight): 6.0-12% of Si, 0.01-2% of Ba, 0.1-1% of Ce, 0.1-0.6% of Mn, 0.01-0.04% of Ti, 0.2-0.4% of Mg, Fe being less than 0.2% and the rest of Al. by the addition of Ba, morphology of Si phase can be changed. The Si phase is changed from a lamellar structure into a fibrous structure or fine granules, thus making eutectic silicon to be uniformly distributed in an alpha (Al) matrix, playing a modification effect and raising plasticity of the alloy. With the addition of Ce element, the Ce element can be combined with Al and Ba, forming a fine precipitated phase dispersed in the matrix, effectively leading to pin dislocations and enhancing strength of the alloy.