Welding robot with positioning function

The utility model relates to the technical field of welding robots, and discloses a welding robot with a positioning function, which comprises a manipulator, the front end of the manipulator is fixedly connected with a support, when the welding robot with the positioning function is used, a pipeline needing to be aligned and welded penetrates through a positioning ring, at the moment, an air cylinder is started, and then the pipeline is aligned and welded. An output shaft of the air cylinder can drive a pushing column to move together through a circular plate and a speed reduction spring, then the pushing column pushes a sliding block, the sliding block can drive a supporting rod to move together due to friction force when pushed, and then the supporting rod drives a positioning block to position a pipeline needing to be welded. When the sliding blocks are pushed by the pushing columns, the three sets of sliding blocks can contract towards the middle through the arc-shaped rods, meanwhile, the arc-shaped spri