Abstract: The mechanical properties and microstructure evolution of 20 mm thick 7075-T6 aluminum alloy plate with different thickness layer were studied by means of metallographic microscope, scanning electron microscope, texture analysis and tensile test.The results show that, the mechanical properties and microstructure of different thickness layers are not uniform.From the surface layer to the central layer of the plate, the grain morphology presents a pie shape and the thickness decreases gradually.The texture strength of Copper, S, Brass increases gradually, but the strength of Cube-ND, Goss texture and random orientation texture decreases, and the strength of Cube texture increases first and then decreases. Due to the difference of the influence of texture composition and grain morphology on the strength of different thickness layer, the strength increases from the surface layer to the sub-central layer, and decreases slightly in the central layer.The elongation is mainly related to the grain morphology, and gradually decreases from the surface layer to the central layer.The fracture modes are mixed-type fracture, the transgranular fracture ratio in the surface layer is large, and the intergranular fracture is the main fracture in the central layer.