<p>The thermomechanical treatment was proposed to improve the mechanical properties of Al–Zn–Mg–Cu alloy. The effect of TMT on the mechanical properties of the alloy was explored by hardness, tensile tests, and friction and wear tests. The 3D morphologies, friction and wear morphologies, and fracture morphologies of the alloy were observed by the scanning electron microscopy and confocal laser scanning microscope. The transmission electron microscope was used to analyze the microstructure of the alloy. The results showed that the mechanical properties of Al–Zn–Mg–Cu alloy were significantly improved by TMT. A certain number of dislocations were introduced after the TMT, increasing the dislocation density and enhancing resistance to dislocation motion. The introduction of dislocations promoted the formation of precipitates, while the precipitates pinned the dislocations motion. Therefore, the mechanical properties of the alloy were significantly improved by dislocation and precipitation strengthening. After T83 treatment, appropriate dislocations were introduced, and the matrix precipitates were numerous and uniformly distributed, resulting in the best-combined effect of dislocation strengthening and precipitation strengthening, which significantly improved the mechanical properties of the alloy. The hardness, tensile strength, friction coefficient, and wear amount were 186.8 ± 1.8 HV, 582 ± 11.4 MPa, 1.409, and 6 mg, respectively.</p>