A new method is developed to measure the wave surface elevation in a wave basin. A thin film of tiny granules floating on the free surface ensures the formation of the dot grid pattern on the wave surface. The dot grid pattern is generated by a high-brightness projector. The granule film has little influence on the wave propagation in a wave basin. The measuring system is validated by the experiments of the propagation of solitary wave in water of uniform depth. It turns out that the time series of the surface elevation measured by the multi-lens stereo reconstruction method agree well with that measured by wave gauges. The errors of the measuring system are discussed. This work sheds a light on measuring the local wave field with high precision and efficiency in laboratory.