Abstract: The tube bundle of heat exchange apparatus may generate flow induced vibration（FIV）under the fluid force. Excessive FIV can cause damage to the heat exchanger components, especially the U-bend section of the nuclear steam generator in two-phase flow. Because of the complexity of two-phase flow and complex structure of tube bundles and strong coupling effect between them, there exist three key mechanical problems of FIV of Tube Bundles in two-phase flow: modeling of two-phase flow, identification of kinetic parameters of FIV and study of FIV mechanism in two-phase flow. In the paper the view of the three above points are reviewed and discussed, and problems to be solved are proposed.