The invention discloses a large-sized workpiece welded intelligent robot device, relates to robot technology, in particular to the robot device based on visual control technology. The device consists of a robot body, a sensing system, a robot controller and a welding auxiliary mechanism. The welded robot is provided with nine moving shafts, including three macrographic moving translational moving shafts, three microscopic moving translational moving shafts and three rotating shafts. The robot body comprises a robot frame and a robot head which is arranged on a transverse arm of the robot frame, and the robot frame consists of the three macrographic moving translational moving shafts, namely a horizontal lead rail, an upright post and the transverse arm. The robot head consists of the three microscopic moving translational moving shafts, the three rotating shafts and a welding gun. The robot frame provides the large-scale three-dimensional movement of the robot; the precision of macrographic moving movement is compensated by the microscopic moving mechanisms of the robot head which also provides rotating freedom of motion. The robot device can meet the movement requirements of large scale and precise positioning for the welding operation of large-sized workpieces. Through the visual sensing technology and intelligent visual controlling technology, the device can improve the automatic welding quality and efficiency of the welded robot.