In recent years，Tianjin’s policy environment and platform construction to support the digital economy have been continuously optimized，which has guided the digital economy to flourish in technological innovation，industrial system，industrial scale，integration and application，and promoted the formation of new advantages in economic development. Entropy method quantitatively fits the comprehensive index of digital economy development in Tianjin，and it shows that the digital economy in Tianjin has maintained a rapid growth since 2000. Further using ARIMA model to predict，Tianjin’s digital economy will continue to maintain a rapid growth trend in the future；Through the calculation of the improved economic growth model，the digital economy has an important positive impact on the overall economic development of Tianjin. However，during the development of Tianjin’s digital economy，there are still some problems in the independent innovation of digital technology，the supply of relevant talents and the integration with the real economy. It is also necessary to better release the digital dividend and promote the high-quality development of Tianjin’s real economy by supporting digital technology research and development，strengthening talent introduction and education，deepening the application of integrated innovation，and optimizing the supply of relevant systems and policies.