The invention provides a control system for a welding robot. The control system comprises a laser vision component, a controller, a servo driver and a robot station, wherein the laser vision component is used for scanning the shape of a to-be-welded workpiece to acquire workpiece shape data; the controller is connected with the laser vision component, and is used for processing the workpiece shape data to acquire corresponding weld joint track data; the servo driver is connected with the controller and the robot station, and is used for driving a linkage motion mechanism in the robot station to perform three-dimensional space motion according to the weld joint track data; the linkage motion mechanism, a swinging component and a welding gun arranged on the swinging component are arranged in the robot station; the linkage motion mechanism performs three-dimensional space motion; the swinging component is connected with the linkage motion mechanism, and can rotate and swing in the height direction in a three-dimensional space; the to-be-welded workpiece is erected and fixed to the robot station; and the linkage motion mechanism and the swinging component drive the welding gun to weld the workpiece according to the weld joint track data of the workpiece. Through the adoption of the control system, the welding robot is applicable to workpieces with various shapes, and can accurately weld the workpieces with different shapes.