In order to emerge the surface low stretch of auto body panel, we study the mechanism, dent test methods and influencing factors of low stretch on the auto body panel. As the traditional sheet metal forming CAE analysis software has not the function of the specific low stretch surface defect analysis at present, we propose low stretch surface defects diagnostic methods and solutions, and develop a special defect analysis software module. Through analyzing the drawing processes on the auto outer door panel, we diagnose and resolve low stretch defect on the auto body panel, and prove that the method of analysis and software module are effective. And then we introduced some methods to optimize the adjustment amount of metal flow and the stamping dies for low stretch.