High-strength and high-corrosion-resistance cast aluminum alloy and pressure casting preparation method thereof

The invention provides high-strength and high-corrosion-resistance cast aluminum alloy and a pressure casting preparation method thereof. The alloy is prepared from, by a certain weight percent, Si, Mg, Fe, Mg, Zn, Sr, Cu, M and the balance Al, wherein M is at least one element of Ti, Zr and V, or the element RE is added in M. After the high-strength and high-corrosion-resistance cast aluminum alloy is subjected to pressure casting, the room temperature tensile strength sigma b of alloy not subjected to heat treatment is larger than or equal to 315 MPa, the room temperature ductility sigma of the alloy not subjected to heat treatment is larger than or equal to 3.0%, and good corrosion resistance is achieved; and the alloy can be applied to automobile parts without ageing or solid solution heat treatment, and the requirement for light automobile development is met.