Based on the ecological situation theory and the knowledge-based view, this study uses panel data from 1459 listed manufacturing enterprises from 2015 to 2023 to explore the mechanism of the impact of enterprise niche on innovation spillover effects. The findings reveal that the two-dimensional characteristics of enterprise niche-niche state and niche potential-exert a positive impact on innovation spillover effects. Furthermore, knowledge coupling acts as a mediator between these two niche dimensions and innovation spillover effects. Additionally, resource dependence is found to negatively moderate the relationship between niche potential and innovation spillover effects.