Abstract: Flexible low-frequency transmission system contains power electronic equipment such as AC/AC converters, which leads to the dynamic coupling of the control link in a wide frequency band, and then results in wide-band oscillation problems. At the same time, compared with the DC transmission system, the flexible low-frequency transmission system exhibits inter-frequency interaction characteristics. Therefore, its dynamic characteristics are more complex, and the problem of wide-band dynamic interaction is more prominent. Solving the wide-band oscillation problem of the system is an important prerequisite for system stability. First, it is expounded that the flexible low-frequency transmission system can be applied to three types of power transmission scenarios, and on this basis, the wide-band dynamic interaction processes that may exist in the system under different application scenarios and the oscillation phenomenon that exists in projects are analyzed. Then, the wide-band oscillation problem and suppression strategies of flexible low-frequency transmission system are summarized, and the deficiencies in the current research on wide-band oscillation analysis and suppression are pointed out. Finally, the prospects in oscillation outlook, mechanism and suppression methods of the wide-band oscillation in the flexible low-frequency transmission system are put forward, providing reference for the follow-up research on the wide-band oscillation of the flexible low-frequency transmission system.