The articulated rotating speed is one of the important parameters to determine the drive devices and actuating devices of joints for legged robots. Compared with the small-scale multi-legged robots, the range of the output speed of the joint should be as accurate as possible for the large-load-ratio multi-legged robots. To reasonably select the devices of joints, the maximum walking speed method is proposed to quickly and accurately obtain the range of articulated rotating speed by taking an electrically driven large-load-ratio six-legged robot as an example. To prove the rapidity, accuracy, and conciseness of the maximum walking speed method, the analyses of the forward kinematics and inverse kinematics of the robot are implemented based on the Denavit-Hartenberg method. However, only one range of articulated rotating speed is effectively confirmed in a single leg. Through rotating one of the joints to achieve the maximum speed index of the robot, the maximum walking speed method is employed to establish the mathematical relationships between the articulated rotating angles and the maximum walking speed index of the robot. The ranges of the output speeds of all joints are accurately obtained. The simulation verification and walking experiments of the prototype are, respectively, carried out. The results of the simulation and walking experiments show that the maximum walking speed method is reasonable and effective in calculating the range of articulated rotating speed. The proposed method in this paper can be reliably applied to the development of large-load-ratio multi-legged robots. INDEX TERMS Large-load-ratio six-legged robot, articulated rotating speed, rotation angle, maximum walking speed method.