Abstract: Effects of cryogenic rolling on the microstructure and mechanical properties of solutionizied Al-4.5 Cu-1.5 Mg-0.6 Mn-0.2 Ti-0.1 Zr alloy were studied by means of optical microscope（OM）, X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The results show that the second phase particles of solid solution plate after cryogenic rolling are chaindistributed along the crystal boundary and the number increases, mainly is θ-Al₂ Cu phase. After cryogenic rolling, the grains of the plate are refined and the dislocation density increases significantly. At this time, the tensile strength of the alloy reaches 610 MPa, which is increased by 168 MPa compared with the solutionizied plate, and the increase range is achieved by 38%and has an elongation rate of 10.3%. The contribution of dislocation enhancement to the performance improvement of different states is calculated, and the dislocation reinforcement effect of cryorolled plate is the most significant. The texture type changes from Rotated Copper of solutionizied plate to α-fiber of cryorolled plate. In addition, the fracture mode of the cryorolled plate is mainly a mixed fracture mode dominated by toughness fracture.