Abstract: The gravity sand mold test block of ZL205A high strength and toughness aluminum alloy was prepared,and the chemical composition,microstructure and mechanical properties of the alloy were analyzed.The results show that,the microstructure of the prepared ZL205A cast sample （Al） grain is fine and uniform,and the grain size reaches level 7.5,and the average size of most grains is about 50μm.The supersaturated solid solution is formed by adjusting ZL205A solid solution treatment process,and improve the first solid temperature and the use of double solid treatment process,ZL205A aluminum alloy θ（Al₂Cu） phase and T(Al₁₂Mn₂Cu) phase at α （Al） grain boundary is significantly reduced,and the as cast precipitated structure is more fully dissolved.After the two-stage solid solution treatment process,the α （Al） grain boundary is fine and pure,and a large number of uniformly dispersed secondary strengthening phases are precipitated from the matrix.At the point,the tensile strength reaches 542 MPa,the yield strength reaches 445 MPa,the elongation is 6.5%,and the strong plastic product reaches 3.52 GPa·%,which is 12.7%,12.1%,62.5%and 83.3%higher than that of 535℃/12 h conventional process,respectively.