Abstract: In order to implement autonomous walking of quadruped robot without prior knowledge of rugged terrain, a motion control method for quadruped robot is proposed. In this method, intermittent crawl is selected as the main gait, and the crawling motion is separated into several individual control tasks: the position of the center of mass is adjusted by calculating the ratio of the stability of inner falling and outer falling based on NESM (normalized energy stability margin) criteria; the slope of the terrain is adapted by mapping the coordinates of the toes; the height of the robot is controlled by adjusting the lengths of the legs; and the posture of the robot is recovered based on the information of the attitude sensor. Simulations and experiments prove that the robot walks stably on rugged terrain, only relying on internal sensors, which proves the effectiveness and reliability of the proposed method.