This application provides a depth-map-based ground detection method and apparatus. The method includes: screening first sample points according to depth values of points in a current depth map; determining space coordinates of the first sample points, and determining space heights of the first sample points according to current gravity acceleration information and the space coordinates; screening second sample points in the first sample points according to the space heights; determining an optimal ground equation according to space coordinates of the second sample points; and determining a ground point in the depth map by using the optimal ground equation. Because the accuracy of the sample points that undergo secondary screening is high, the ground detection precision is high. Because this application is not excessively dependent on a depth value, the calculation complexity is low, and operation can be performed on various hardware.