To evaluate the motion image quality of binocular parallax based stereoscopic displays more objectively and precisely, the evaluation method is established based on two dimensional (2D) motion blur evaluation model and three dimensional (3D) perception experiment. The 2D motion blur simulation is applied on the binocular parallax images, and then displayed on the 3D space. After that, the comparison perception experiment is completed between real motion blur perception and simulation. The experiment result shows that factor"parallax"has no significant effect on motion blur perception. Based on these, the average motion blur level of two parallax images is used to establish objective motion blur evaluation method of binocular parallax based stereoscopic displays. The proposed method makes the motion image quality evaluation of binocular parallax based stereoscopic displays more objective and precise. Meanwhile, it provides reference for the motion image quality improvement in stereoscopic displays.