<p>To establish a constitutive model suitable for high temperature and wide strain rate conditions in friction stir welding (FSW) of 2219 aluminum alloy thick plate, the high-temperature deformation behavior of 2219 aluminum alloy was investigated via thermal compression experiments within a wide range of deformation temperatures (573–773&#xa0;K) and strain rates (10⁻²–10³&#xa0;s⁻¹). The experimental results indicate that flow stress decreases with increasing temperature and decreasing strain rate, and discernible disparities exist in the variation tendencies of the flow stress under diverse deformation conditions. Based on the experimental data, a strain-compensated Arrhenius constitutive model and an Arrhenius constitutive model considering the comprehensive influence of thermal deformation conditions were established. Furthermore, the prediction ability of the two models for high-temperature deformation behavior was also evaluated. The correlation coefficients (<i>R</i>) between the experimental and predicted flow stresses for two models were 0.903 and 0.991, respectively, and the average absolute relative errors (AAREs) between the experimental and predicted flow stresses of the two models were 11.87% and 4.72%, respectively. The results show that the strain-compensated Arrhenius constitutive model has a large error in the prediction of the initial stage of material deformation and cannot describe the differences in flow stress variation trends under different deformation conditions. The Arrhenius constitutive model considering the comprehensive influence of thermal deformation conditions has higher accuracy and can accurately predict the high-temperature deformation behavior of the material in the whole deformation stage over a wide range of temperature and strain rate.</p>