This paper examines deeply how technological learning routine mediates the relationship between knowledge attributes and firms’ innovation performance. Based on survey data and structural equation modeling method, this paper conducts an empirical study to validate the theoretical hypotheses. The results show that the intensity of technological learning routine partially mediates the relationship between knowledge attributes and firms’ innovation performance. Specifically speaking, the intensity of knowledge maintenance routine and that of knowledge reactivation routine mediate the relationship between knowledge tacitness and innovation performance, and the intensity of knowledge reactivation routine mediates the relationship between knowledge heterogeneity and innovation performance. Besides, firm size plays moderating effects on the relationships between knowledge tacitness and the intensity of knowledge maintenance routine and that of knowledge reactivation routine.