A passive excitation-type bridge damage evaluation method: excitation teeth uniformly distributed on a single excitation wheel are used for performing passive excitation at a fixed excitation frequency on a bridge deck, and an acceleration sensor is used for acquiring an acceleration signal transmitted to the excitation teeth from the bridge deck. By means of extracting a maximum value point of an equivalent acceleration speed from a time-frequency analysis result, a stiffness mutation moment is determined to have been detected, and according to an inflection point in a corresponding power spectrogram, a bridge damage position is determined and a degree of damage is determined.