A resonant method is proposed to measure the optical-pulse-propagation delay of the Fabry-Perot filter. The Fabry-Perot filter is placed in a resonant cavity, so its transmission delay is converted to the decrease of the resonant fundamental frequency, according to the relationship between the cavity length and the resonant frequency. The change in the fundamental frequency of the resonance is measured to be 0.167 MHz, which corresponds to a change in the length of the resonant cavity of 3.570 m. Subtracting the package length, the transmission delay is 1.542 m. No other parameters are needed in the scheme, such as the reflection coefficient of specular surface, the fineness and so on, it is easy to get noticeable propagation delay of high-finesse Fabry-Perot filters, even a minor-sized one. A transmission delay of 1.581 m is obtained by spectral analysis, which is a verification to the above experimental results.