Abstract: Some parameters, such as damage strain, triaxial stress and strain ratio, were considered as a ductile damage standard of Q235 steel sheet, taking forming conical part as an example, using ABAQUS finite element software to simulate ductile damage of Q235 steel sheet during single point incremental forming, and the related experiments were carried out. The results show that on the forming region of Q235 steel sheet, the thickness of the sheet metal is uneven. The change rates of thickness at the bottom and top of the conical parts are symmetrical, the middle area of the conical part is the thinnest, where the ductile damage appears easily. The results of simulation can predict accurately the ductile damage position of Q235 steel sheet, the experimental results also prove the correctness of finite element model.