Abstract： The speed measuring mechanism base on two degree freedom universal wheel was designed, which consisted of a two degree of freedom roller, a rotary encoder, an angular displacement sensor and a horizontal attitude sensor and so on. When the robot moved, its attitude angle and angular velocity were detected by the level posture sensor, its velocity direction was detected by the angle sensor, and its speed was measured by the photoelectric encoder, thus, the motion state of the robot can be obtained by this measuring device, and the relationship between the motor input and control point motion was also established, provide basis for the precise operation of the robot.