Three processes which combined equal_channel angular pressing (ECAP) with heat t reatment were applied to fabricate super_high strength fine 7050 Al alloy. Varia tions of microstructure parameters of precipitates in 7050 Al alloys were analyz ed by using small angle x_ray scattering technique. The variations of mechanical properties and mechanism of strengthening in 7050 Al alloys were explained in the paper. Experiments discovered that “pre_ECAP solid solution treatment and post_ECAP aging treatment" was a proper process, with which the ultimate tensile strength was increased to 677MPa, and elongation to failure was improved to b e 15% or so.