Under the condition of socialist market economy, intergovernmental cooperation of Beijing-Tianjin -Hebei region has become the inevitable choice of regional economic integration. At present, the international cooperation consciousness of Beijing-Tianjin-Hebei integration is generally recognized, the mechanism is also initially established, and its effectiveness has gradually revealed, but still faces some problems and difficulties. Through investigation and study, the paper discusses the main problems of the international cooperation in the process of Beijing-Tianjin-Hebei integration, putting forward the general requirements and the basic principles of intergovernmental cooperation mechanism in the process of Beijing-Tianjin-Hebei integration, thus establishing the five-in-one intergovernmental cooperation mechanism of Beijing-Tianjin-Hebei including execution mechanism, supervision and restraint mechanism, coordination mechanism, trust mechanism, dynamic mechanism, in order to help promote the coordinated development of Beijing-Tianjin-Hebei region.