“Three cities and one district” is the main platform for Beijing to build the international science and technology innovation center，and occupies an important position. The “three cities and one district” has its own functional orientation and development characteristics. It supports and promotes the construction of international science and technology innovation center in the aspects of practicing the new national system，exerting the agglomeration effect，and forming collaborative innovation force. There are still some gaps and deficiencies in Beijing’s construction of an international science and technology innovation center，which requires “three cities and one district” to lead the international science and technology innovation construction out of a new path.