Through the double-pass compression process of press, combined with the heat treatment, the influences of strain rate on the mechanical properties of 7050 aluminum alloy were studied by room temperature tensile test and microstructure characterization method, and based on the quantitative analysis of microstructure, the strengthening mechanism of  alloy during the compression at different strain rates was investigated. As the strain rates of the first/second pass increased from 0.003 s-1/0.006 s-1 to 0.1 s-1/0.2 s-1, the average grain size decreased from 52 μm to 36 μm, the small-angle grain boundary fraction decreased from 47% to 37%, the dislocation density reduced from 2.50×1014 m-2 to 1.68×1014 m-2, the contribution value of the large-angle grain boundary strengthening to the yield strength was 11 MPa, the contribution values of the small-angle grain boundary strengthening to the yield strength was 5 MPa and 4 MPa, respectively, and the contribution value of the dislocation strengthening to the yield strength decreased from 88 MPa to 69 MPa. The results show that the strength of alloy after solution-aging treatment decreases with the increasing of the strain rate, the strength change of alloy caused by the strain rate is mainly dominated by the dislocation strengthening, and the large-angle and small-angle grain boundaries have no obvious influence on the strength of alloy. As the strain rate increases, the sum of the contribution values for dislocations, large-angle grain boundary and small-angle grain boundary to the yield strength of alloy decreases resulting in a decrease in the strength of alloy.