The invention discloses a rotating blade underwater dynamic deformation binocular measurement system of a composite material propeller model, and relates to the technical field of propeller testing. The system comprises two cameras, white light stroboscopic light source equipment, a synchronizer, a software system, optical auxiliary equipment, a target and a dynamometer; the two cameras are arranged beside an observation window in the side of a water drum test section; the white light stroboscopic light source equipment is arranged at an observation window in the upper portion of the water drum test section; the synchronizer is connected with the cameras, the software system and the dynamometer and controls synchronous work of the cameras, the software system and the dynamometer; the target is arranged at a to-be-tested area, and the two cameras shoot at least eight pairs of speckle images, at different positions and in different directions, of the target; the software system is in charge of collecting the speckle images and conducting subsequent correlation analysis; the optical auxiliary equipment is arranged on the observation window in the side of the water drum test section. According to the system, through non-contact optical measurement, the speckle images of blades are obtained, real-time deformation features of composite material blades are obtained correlation analysis, and thus guidance in design and optimization of the composite material propeller is achieved.