The present invention belongs to the technical field of image measurement, and provides a motion measurement method and apparatus applied to a large multi-paddle wave simulation system. When the motion of the wave maker is measured, firstly site images are collected by the cameras; the mark point on each wave making paddle in the image processing boards is identified; and a central position is computed. Then, the central position is contrasted with the initial position to calculate displacement of the image plane and convert the displacement into the displacement on a physical space in combination with calibration parameters. Next, data is transmitted to the computer through the EtherCAT network, and coded identification is conducted on the data. Finally, comparative analysis is conducted on a measured value and a target value of the motion of the wave making paddle in the computer, thereby obtaining motion information of the wave maker. In the present invention, when the motion of the wave maker is measured, the problems of difficult target recognition and unstable motion tracking caused by nonuniform illumination in the experiment site as well as the problems of great time consumption of an image analysis algorithm and low efficiency of data transmission of multiple camera systems are fully considered.