The temperature change of the die surface in practical aluminum alloy die casting process was analyzed,and a 2D model was formulated on the basis of a deep concave round cavity without sliding core to analyze thestress distributions along the die surface in detail. Equipment was designed to test the thermal state of the die steelin different thermal loading conditions. The results of stress analysis showed that, the value of thermal stress (maximum1.5 GPa) caused in the die filling and die spraying stages was larger than the mechanical stress (maximum 85 MPa)caused in the die locking stage. The results of the thermal check experiment showed that there were three stages ofdie dissolving, and that the stress distribution shown by the samples’ cracking routine was close to the die surfacestress analysis. The temperature change of the die surface was analyzed, and a 2D model was formulated on the basis of a deep concave round cavity without sliding core to analyze the distribution distributions along the die surface in detail. Equipment was designed to the results of stress analysis showed that, the value of thermal stress (maximum 1.5 GPa) caused in the die filling and die spraying stages was larger than the mechanical stress (maximum 85 MPa) caused in the die locking stage. The results of the thermal check experiment showed there there were three stages of die dissolving, and that the stress distribution shown by the samples’ cracking routine was close to the die surfacestress analysis.