The high-temperature flow behavior of Al–Cu–Mg alloy is studied by the hot compressive tests over wide range of strain rate and forming temperature. Considering the negative effects of the interfacial friction on the heterogeneous deformation of specimen, the measured flow stress was corrected. The effects of processing parameters on material flow behavior are discussed. Based on the measured stress–strain data, a phenomenological constitutive model, which considers the coupled effects of strain, strain rate and forming temperature on the flow behavior of alloy, was proposed to describe the compressive behavior of the studied Al–Cu–Mg alloy. The proposed constitutive model correlates well with the experimental results, which confirms that the proposed model can give an accurate and precise estimate of flow stress for the studied Al–Cu–Mg alloy.