基于参数曲面拼接原理，提出了车身覆盖件仿真成形几何建模中复杂曲面造型曲面片划分的准则和评价拼接质量的准则，引入了相邻曲面公共连接线上法线夹角αｍａｘ作为衡量曲面片连接光顺度指标，以车身前门外板覆盖件冲压成形仿真几何建模为实例，应用上述准则和αｍａｘ指标，其建模质量和仿真结果都很理想，提高了建模效率和质量。实践证明，本文提出的准则和αｍａｘ指标是合理可行的。 Based on the principle of parametric surface mosaic, the criteria for surface division of complex curved surfaces and the criteria for evaluating the quality of the mosaic are proposed. The normal angle αmax of the common connecting surface of adjacent surfaces is introduced as a measure of surface patch The smoothness index of the connection is taken as an example, taking the above-mentioned criterion and αmax index as an example, the modeling quality and the simulation result are both ideal and the modeling efficiency and the quality are improved. Practice has proved that the proposed criteria and αmax index is reasonable and feasible.