The invention discloses a ground obstacle detection method based on the binocular stereo vision of a robot, which belongs to the technical field of intelligent robots, and comprises the following steps that: according to the binocular baseline length and the focus, the ground parallax values of all rows in an image are analyzed through the geometrical configuration of the known image; based on the ground parallax values, a back projection model calculates the three-dimensional coordinates of a scene point corresponding to a pixel so as to initially judge whether the pixel belongs to an obstacle or a ground point; the obstacle and the ground point are respectively endowed with different colors; the results are post-processed and the false obstacle is removed; and three-dimensional errors are removed and a grid map is established. The method is applicable to various complicated indoor environments, can precisely identify various obstacles, has very high real-time performance, and provides very good preparation conditions for the robot to avoid obstacles.