Magnesium alloys are valued by industry for their lightweight structures. Magnesium alloy are mainly produced by warm forming because the sheet formability is poor at room temperature. The mechanical properties of magnesium alloy AZ31, such as stress-strain curves and damage values at different elevated temperatures, were obtained by this study using a computerized screw universal testing machine. Freudenthal fracture criteria were used to obtain the forming limit at distinct temperatures. The forming limit analysis proceeded during the sheet metal forming process at various elevated temperature. The fracture’s forming load, stroke, and position were determined for different working temperatures of the sheet metal forming process for AZ31, using a finite element simulation combined with the ductile fracture criteria. Finally, the predicted values were compared with the experimental results during the sheet metal forming process. The simulation results agreed with the experimental values for the fracture forming load, stroke, and position of the sheet metal forming process. The feasibility of the present method was confirmed to predict forming limit during the sheet metal forming process for different elevated temperatures. A finite element analysis for forming limit prediction would be beneficial to the design of sheet metal processes for AZ31 magnesium alloys.