In the present study, the stress-strain relationship of 6063-T5 aluminum alloy over wide ranges of temperatures and strain rates was investigated. Firstly, the quasi-static tensile tests and high temperature split Hopkinson pressure bar (SHPB) tests were carried out for 6063-T5 aluminum alloy. In the tests, the experimental temperature ranged from room temperature to 350℃, and the dynamic strain rate was 500/s-6000/s. Secondly, the effects of temperature and strain rate on mechanical properties of materials were discussed. The results showed that 6063-T5 aluminum alloy had obvious temperature softening effect and strain rate hardening effect, but strain rate softening effect may also occur under certain temperature conditions. Thirdly, the fracture morphology of tensile specimen and the metallographic structure of dynamic compression specimen under different temperature and strain rates were analyzed. Finally, by improving the fitting method and constitutive model, the modified Johnson-Cook constitutive model for 6063-T5 aluminum alloy was obtained. Compared with the traditional one, the modified Johnson-Cook constitutive model can predict the mechanical behavior of 6063-T5 aluminum alloy more accurately under high temperature and dynamic conditions.