Measuring and calculating the competitiveness of digital economy at the urban level has always been a difficult problem in academia. This report attempts to construct an index system of urban digital economy competitiveness with the core of urban digital innovation competitiveness，urban digital talent competitiveness and urban economy and infrastructure competitiveness，and select 30 major cities in the world. The competitiveness of digital economy is quantitatively evaluated and analyzed. The study finds that American cities have significant advantages in the competitiveness of digital economy，and they are in a significant leading position compared with other cities. There is a strong positive correlation among the three secondary indicators of urban digital economic competitiveness，which indicates that the structural factors of urban digital economic competitiveness are closely related to each other. American cities have absolute advantages in the competitiveness of urban digital talents and innovation. However，Asian cities have begun to occupy a dominant position in the competitiveness of urban economy and infrastructure. At the same time，two major cities in China，Beijing and Shanghai，have entered the competition of urban economy and infrastructure. Although Beijing and Shanghai are among the top ten cities in the list，there is a big gap in the competitiveness of urban digital talents and urban innovation compared with the United States and other developed countries. The current pattern of digital economic competitiveness at the global urban level is characterized by the absolute dominance of the United States，the strong competitiveness of European developed countries in urban innovation and talent，and the subsequent dominance of cities in emerging Asian economies in economic and infrastructure competitiveness.