We extract the foreground region of stereoscopic video by combining the grayscales of left and right view, and synthesize the two pictures into a disparity map, then extract the horizontal parallax and calculate the depth parallax. Finally, we build the depth parallax-visual discomfort model on the basis of subject assessment and optimize the visual discomfort model by considering the luminance influence. Experimental results indicate that the error rate is less than 5% between calculated value and human subjective evaluation results, and most video error rates are less than 1%. The evaluation model is more accord with human subjective perception results and has good practicability, which provides a reference for the stereo video comfort evaluation.