The mechanical properties and corrosion resistance of a novel Al-Zn-Mg-Er-Zr alloy under different aging processes were systematically studied. The microstructure of the alloy was analyzed by using EBSD、XRD, SEM , TEM to understand the relationship between the best comprehensive properties of the alloy and its microstructure mode. It is found that the excellent two-stage aging process is 90℃/12h+145℃/18h. The related mechanical properties including ultimate tensile strength (UTS) and elongation were 388 MPa and 14.0%. The susceptibility to exfoliation corrosion is PB. At the same time, the main strengthening phase（G.P zone and η′ phase）of the alloy are numerous precipitated in matrix, the η phase at the grain boundary is discontiguous distribution.