Abstract: The thermal deformation of 5052+Er alloy at high temperature was carried out with the Gleeble-3500 type thermal/force simulation test machine and the effects of deformation temperature and strain rate on the high temperature compression behavior of 5052+Er alloy were studied. The results show that when the strain rate is 0.01 s^-1, the true stress-true strain curve presents typical dynamic recrystallization features; When the strain rates are 0.1 s^-1 and 1 s^-1, the curves are characterized with dynamic recovery; When the strain rate increases to 10 s^-1, after the flow stress reaches the peak value, the zigzag wave appears, and the dynamic recrystallization of the alloy occurrs; With the increasing of the deformation temperature and the decreasing of the strain rate, the rheological stress of the 5052+Er alloy decreases gradually, and the rheological stress equation of the thermal compression deformation of 5052+Er alloy is σ=95.42\left\\left(\frac\dot\varepsilon \exp \left(\frac155500R T\right)2.69 \times 10^18\right)\right\^0.1877+\sqrt\left(\frac\dot\varepsilon \exp \left(\frac155500R T\right)2.69 \times 10^18\right)^0.3754+1, and the errors between the calculated values of the peak stress and the measured values under different thermal deformation conditions are lower than 10%.