_{:To improve the straightening accuracy of magnesium alloy plates, the neutral layer offset pattern of magnesium plates needs to be analyzed. At room temperature, the plasticity of magnesium alloy is poor and the tensile asymmetry is also large. And when the magnesium plate is straightened at room temperature, improper control of the amount of pressure will cause the straightening effect of the plate to be seriously affected. Therefore, the magnesium plate is often used to improve the straightening accuracy and the temperature is an important factor affecting the pulling and pressing asymmetry of magnesium plate. In this paper, based on the CaBa2004 tensile-compression asymmetry yield criterion and using the basic theory of elastoplastic mechanics, the formula for calculating the neutral layer offset in the straightening process of AZ31B magnesium plate is derived. A thermodynamically coupled straightening model was established using ABAQUS finite elements to derive the neutral layer offset law at different temperatures, and using experiments, the neutral layer offset theory was experimentally verified.}