A dynamic damper in a lighting driving circuit for limiting an inrush current includes a damper circuit and a timing circuit comprising capacitor. The damper circuit is connected to the timing circuit. When an input voltage is provided to the dynamic damper, the capacitor begins to be charged and the capacitance-voltage of the capacitor rises. The damper circuit enters to a first working state and generates a dynamic damper resistor value. When the capacitance-voltage of the capacitor is greater than a first threshold voltage, the damper circuit enters to a second working state and the dynamic damper resistor value begins to decrease. When the capacitance-voltage of the capacitor is greater than a second threshold voltage, the damper circuit enters to a short-circuit state, and the dynamic damper resistor value decreases to zero to facilitate the normal work of the power source converter.