针对传统产品的关键零部件由于服役时间过长、损伤严重而无法再制造的问题，提出结构功能衍生系数的概念。通过研究不同设计参数组合下零件再制造性的变化，建立结构再制造性与设计参数的映射函数模型。并构建衍生系数矩阵及其导数矩阵，反映设计参数改变对结构再制造性变化及变化趋势的影响，为关键件的参数优化设计提供依据。提出基于结构功能衍生系数的主动再制造设计方法，通过参数优化和预设再制造时机下限，保证产品关键零部件的可再制造性。以6L240型号柴油机曲轴为例，验证该方法的有效性和可行性。

Due to long service time and serious damage,key components of traditional product can’t be remanufactured. The concept of the structural function derivative coefficient is given to solve the problem. Through simulation analysis of key components with different parameter combinations,the mapping functions between structural remanufacturability and design parameters are obtained,and then,derivative coefficient matrix and its derivative matrix are established,which reflect the influence and the influencing trend of parameters variations to structural remanufacturability,and provide the basis for parameters optimization design of key part. The predecisional remanufacturing design method based on derivative coefficient matrix and its derivative matrix is given,the remanufacturability of key component is ensure by optimization design and presetting remanufacturing time limit. A 6L240 engine crankshaft was given as an instance to validate the effectiveness and feasibility of the method.