At present，the location selecting of innovative enterprises in the world is associated with the revival of the metropolitan inner city. The so-called“innovation square”is the phenomenon of gathering and innovating enterprises in the neighborhoods of urbanized living environment. Based on the in-depth study of the Cambridge Kendall Square innovation district，it is found that the creation of public space is the essence of promoting the revitalization of urban neighborhoods by promoting the young people and the diversification of the streets. This will help us to understand how to play the role of the main city in activating the innovation vitality of the neighborhood in the context of the“public entrepreneurship，popular innovation”and“new urbanization”strategy，and thus enhance the city's overall innovation capability.