Flying capacitor pre-charging circuit and three-level converter

The invention belongs to the technical field of electronic circuits, and particularly relates to a flying capacitor pre-charging circuit and a three-level converter, the flying capacitor pre-charging circuit is connected with the three-level converter, and the flying capacitor pre-charging circuit comprises a sampling circuit, a charging and discharging circuit and a control circuit; the sampling circuit is used for synchronously sampling the voltage of a flying capacitor of the three-level converter and outputting a sampling voltage, the charging and discharging circuit is used for charging or discharging the flying capacitor, and the control circuit is used for outputting a driving signal to the sampling circuit to control the sampling circuit to synchronously sample the voltage of the flying capacitor. The control circuit is further used for controlling the charging and discharging circuit to charge or discharge the flying capacitor according to the sampling voltage so as to maintain the voltage of the fly