通过对小湾拱坝的弹性有限元计算，分析了坝踵区在拉应力作用下裂缝出现的可能性，进而描述了进行拱坝开裂分析所采用的裂缝模型，并给出了小湾拱坝出现裂缝的可能范围以及坝踵区应力变化的非线性有限元计算成果。讨论了开裂约束条件下拱坝体型优化的数学模型及强度控制指标和开裂深度控制指标。 Through the finite element analysis of the Xiaowan arch dam, the possibility of cracks in the heel area under the tensile stress is analyzed, and then the fracture model used in the cracking analysis of the arch dam is described. Finally, The possible range of occurrence of cracks and the stress change in the heel zone of the nonlinear finite element calculation results. The mathematic model and strength control index and cracking depth control index of arch dam body under cracking constraint were discussed.