The invention discloses a robot bouncing mechanism based on hydraulic drive. A hydraulic cylinder pushes a bilateral rack to drive the center of gravity of a five-rod mechanism which is composed of a belt tooth connecting rod, a second connecting rod and a third connecting rod to move downwards, an spring is stretched to store elastic potential energy at the same time, oil return of the hydraulic cylinder is controlled, the spring is released instantly to drive the whole mechanism to bounce, and the movement reliability is high. By means of the bouncing mechanism, the linear force of the spring is converted into non-linear bounce motive power, and more energy is stored under the condition of the same displacement. The bouncing mechanism takes advantage of hydraulic drive, the hydraulic cylinder is mounted on a drive joint directly, the use of a reducer is avoided, and the structure of a robot is simplified. The obstacle climbing ability and the activity range of the robot are improved notably if the bouncing mechanism is combined with a moving mode. According the bouncing mechanism, movement and power are transmitted in the mode that the rack is meshed with a gear, and thus the robot bouncing mechanism based on hydraulic drive has the advantages of being reliable in operation, long in service life, compact in structure, high in transmission precision and large in transmission power.