The variation rules of key mechanical property parameters  of 7A09 aluminum alloy sheet were obtained by uniaxial tensile tests at different temperatures and strain rates. The results show that under the condition of constant strain rate, the tensile strength and flow stress of 7A09 aluminum alloy increase with the decreasing of temperature, and the elongation after fracture increases obviously with the increasing of temperature. Based on the Fields & Backofen constitutive equation, the stress-strain constitutive model of 7A09 aluminum alloy during warm tension was established, and the strengthening rules of 7A09 aluminum alloy under different temperature conditions were analyzed and discussed. The results show that the strain hardening index of 7A09 aluminum alloy decreases with the increasing of temperature, while the strain rate sensitivity coefficient increases significantly, and the hardening effect of strain rate is significantly enhanced. For the stringer reinforcement by warm forming technology, the finite element simulation was carried out by using the constitutive model, and it is determined that the thinning rate of parts is the minimum when the forming speed is 5000 mm·s-1. When the forming temperature is 175 ℃, the wall thickness distribution of parts is the most uniform, and the minimum thinning rate is only 3.8%.