Based on mark points on the surface of bridge pneumatic model adopting the digital image correlation (DIC) method to handle the pictures captured by CCD video camera in the high frequency, the displacement values of the mark points in the time series are gotten and thus the vibration responses of the bridge are obtained. The fundamental principles of the DIC method and its application are introduced. The reliability, stability and advantages of the method are testified by the comparison of the results with those measured by the laser displacement sensor.