尽管近期大量学者验证了外部知识异质度对企业创新绩效具有倒U型曲线效应，但却没有能够厘清这一效应的内生性机制及其形成原因。本研究基于知识重构和吸收能力的视角，通过采集和分析来自上海、江苏和浙江的261个创新型样本企业问卷数据，识别外部知识异质度与企业创新绩效之间倒U型曲线关系的形成机制。结果表明：外部知识异质度通过促进知识重构正向影响创新绩效、却通过弱化吸收能力反向影响创新绩效；这两种效果相反的中介机制导致外部知识异质度与创新绩效之间产生了倒U型曲线关系。这一发现揭示了企业外部知识异质度对创新绩效影响的内在机理，进一步发展了主流文献的相关研究。

Though the inverse U-shaped relationship between external knowledge heterogeneity(KH) and firm innovation performance has been tested by many scholars recently，few quantitative studies on the endogenous mechanism and reason of the inverse U-shaped relationship between the two have been done. Using a survey data of 261 firms from innovation-intensive industries in east China, this study provides evidence of the inverse U-shaped relationship between the two by introducing two variables of knowledge reconfiguration and absorptive capacity. The empirical research results show external KH exists both the value of knowledge reconfiguration and the trouble of absorbing and transferring. In addition, we find external KH influences innovation performance through two opposite mediating mechanisms which are named knowledge reconfiguration and absorptive capacity. This study deepens our understanding regarding to the intrinsic mechanisms between external KH and innovation performance, and further develops the study of existing literature in this field.