Abstract:    Innovation is the first driving force for enterprise development, but with the world entering a century of unprecedented changes, the increase in supply chain uncertainty has brought major challenges to enterprise innovation. This paper constructed a theoretical model to describe the internal mechanism of supply chain uncertainty affecting firm innovation, and provided a measurement method of supply chain uncertainty and makes an empirical test. It was found that the increase of supply chain uncertainty will inhibit enterprise innovation, mainly due to the resource constraint effect caused by supply chain uncertainty resulting in the reduction of commercial credit financing, and to the value wait-and-see effect caused by the contraction of investment in special assets. The internal digital transformation and the increased transparency of the supply chain, the reform of the margin financing system outside the enterprise and the opening of the capital market can help alleviate the negative impact of supply chain uncertainty on enterprise innovation. The uncertainty of different supply chain entities can inhibit the innovation of enterprises, but compared with customer uncertainty, supplier uncertainty has a stronger inhibitory effect on innovation. From the perspective of enterprise innovation output, supply chain uncertainty also has an inhibitory effect on enterprise innovation output, especially the negative impact on joint innovation. This study has revealed the economic consequences of supply chain uncertainty, and it will provide a new perspective and knowledge for maintaining the security and stability of national supply chain and promoting enterprise innovation.

Key words: supply chain, customer, supplier, uncertainty, innovation