The invention relates to a power oscillation power risk detecting method and system of a fan flexible direct-current grid delivery system. The method comprises the steps that a set-up fan flexible direct-current grid delivery system simulation model is utilized, and disturbance voltage sources of different frequencies are added to a fan access point to acquire the voltage sequence and current sequence of a fan access point wind field side and a flexible direct-current grid side; then an impedance amplitude and an impedance phase angle are determined according to the voltage sequence and the current sequence; then whether the fan flexible direct-current grid delivery system has oscillation risks or not is detected through an impedance analysis method according to the impedance amplitude andthe impedance phase angle. According to the technical scheme, the disturbance frequencies are added to the fan access point of a simulation model to acquire the voltage sequence and the current sequence, the impedance amplitude and the impedance phase angle are determined, a bode diagram is drawn through the disturbance frequencies, the impedance amplitude and the impedance phase angle, the phaseangle margin of the system is determined according to the bode diagram, and whether the fan flexible direct-current grid delivery system has power oscillation risks or not is judged effectively.