A method for assessing an objective quality of a stereoscopic video based on reduced time-domain weighting, which considers a time domain perception redundant characteristic of human eyes during a video perception, includes steps of: through a motion intensity mean value and a motion intensity variance of an undistorted stereoscopic video and the motion intensity mean value and the motion intensity variance of each frame group, determining a motion intensity level of each frame group of the undistorted stereoscopic video; for the frame groups having different motion intensity levels, selecting undistorted reduced stereoscopic images through different frame extracting strategies with different densities; measuring a quality of a simultaneous distorted reduced stereoscopic image relative to the undistorted reduced stereoscopic image; through weighting each quality of the simultaneous distorted reduced stereoscopic image relative to the undistorted reduced stereoscopic image, obtaining a quality of a distorted stereoscopic video relative to the undistorted stereoscopic video.