Digital technology innovation is the technical support for the development of the digital industry and has an important impact on economic and social development in the digital era. International Patent Classification (IPC) at the level of subgroups was used to construct the quantity and quality of digital technology innovation. Based on this, the Outline of National Informatization Development Strategy issued by the Central Committee of the Communist Party of China and the State Council which is the most representative national digital industry policy was taken as the entry point. The panel data of China's listed companies from 2011 to 2020 was used to empirically test the relationship between digital industry policy and enterprise digital technology innovation. The results are as follows. The national digital industry policy has a significant effect on the quantity and quality of digital technology innovation of micro-entities. Heterogeneity test results show that the above enhancement effect is only established in private enterprises, large-scale enterprises and high-tech enterprises. The mechanism test shows that easing financing constraints, relaxing industry access and promoting enterprise digital technology investment are the three channels which national policy incentive affect digital technology innovation. It is helpful for the government to formulate reasonable policies to encourage enterprise digital technology.