Abstract: The microstructure of 7136 aluminum alloy with high Zn content was studied and the variation law of its cast structure and homogenization heat treated structure was discussed. The results show that the microstructure of as-cast 7136 Al alloy contains a large number of quaternary AlZnMgCu phases and fine needle-like or point-like MgZn₂ phases at the α-Al dendrite boundary, and θ(Al₂Cu) and S (Al₂CuMg) phases are not found. The AlZnMgCu quaternary phase with MgZn₂ type structure forms the lamellar non-equilibrium eutectic phase with α-Al, which is distributed around the dendrite boundary. The distribution of Zn, Mg, and Cu in the non-equilibrium eutectic phase is not uniform. After homogenization treatment at 475 ℃ for 12 h, most of the network non-equilibrium eutectic phases dissolve into the matrix, their size significantly reduces, and some fused and granular residual phases form. The remaining residual insoluble phases are the AlZnMgCu quaternary phase and the high melting point Al₇Cu₂Fe phase, and the Al₇Cu₂Fe phase tends to increase with the increase of holding time.