Quadruped robots have advantages in manufacturing cost, operation stability, and difficulty, suitable for substation inspection and other operational scenarios. Based on SolidWorks software, a Quadruped robot with four single-joint legs is designed based on the prototype of the dog animal in nature. The robot has four semi-circular legs and a waist joint and has five degrees of freedom. Based on the designed quadruped robot model, the motion of the quadruped robot with the waist joint is simulated and analyzed in Adams. Finally, experiments are carried out to test the effect of the waist joint of the quadruped robot. The results show that the waist joint helps control the direction of the robot motion and improves the stability of the robot motion.