Abstract: 7005 aluminum alloy for rail transit vehicles annealed at 350℃×2 h was subjected to 2 passes equal channel angular extrusion at room temperature.The optical microscope, scanning electron microscope and electronic tensile testing machine were used to analyze the microstructure, mechanical properties and fracture morphology of the alloy before and after extrusion.The results show that with the increase of extrusion pass, the sample microstructure is refined and the mechanical properties are improved.After 2 times, the grain size is about 3 μm, or even small grains below 1 μm; the tensile strength, yield strength and elongation after fracture are 384.33 MPa, 332.60 MPa and 14.2%, respectively, which increases 53.08 MPa, 79.48 MPa and 2.8%compared with those of the equal diameter angle before extrusion, respectively.The grain refinement is obvious and the mechanical properties are greatly improved.