An Omni-directional mobile manipulator with capability of zero-radius rotation is developed. Mechanism structure of the mobile platform and the manipulator are introduced, and the wheel model of the robot is designed with differential compensation structure. Multi-sensor system comprising ultrasonic sensors, infrared sensors and force/torque sensor are used for achieving precise control for the robot. Meanwhile, motion control of the mobile platform is analyzed, and servo control based on hierarchical structure of the manipulator is proposed. Finally, experiments of the robot are executed, and the results show the error of the platform for forward 4m is 8mm approximately after corrected by ultrasonic sensors, average error of zero-radius rotation is 3.7658mm, average error of re-orientation motion is 0.3mm, which verify the proposed omni-directional mobile manipulator designed reasonable, and can achieve precise operation effectively.