Abstract: By constructing a heterogenous enterprise dynamic equilibrium model and combining theoretical research with quantitative analysis, this paper explores the impact of digital economy on industrial productivity, intra-industry resource integration and social welfare. The findings show that after introducing digital economy, the export critical productivity increases, the changes of the production critical productivity and industrial average productivity are determined by the corresponding critical value of the productivity improvement index, while the degree of the intra-industry production competition is relieved and the degree of the intra-industry export competition is intensified. Through the two paths of changing the factor marginal output and the industrial entry cost, digital economy can exert its effects on the industrial economy at the same time. It has dual effects on the intra-industry resource integration and the social welfare, which means that there exist corresponding critical values of data versus price. On both sides of the critical value, the effects brought over by the digital economy is just the opposite. The value and the changing trend of this relative price critical value depend on such industrial characteristics as the intensity of data factor, the degree of product differentiation, and the industrial trade cost. This research not only builds a theoretical analysis paradigm for industrial digitalization and lays a theoretical foundation for future research on the industrial effects of the digital economy, but also provides a theoretical basis for China to steadily promote the development of the digital economy. The government should implement the precise industrial guidance policies in accordance with the various industrial characteristics and promote the transformation and upgrading of the industrial digitalization according to local conditions.

Key words: digital economy, industrial productivity, intra-industry resource integration, social welfare, heterogenous enterprise dynamic equilibrium model