Overheat dissipation submersed nozzle used for square and round billet continuous casting

The utility model relates to an overheat dissipation submerged nozzle used for square and round billet continuous casting. The overheat dissipation submerged nozzle comprises a nozzle body, a slag line layer, a nozzle inner hole and nozzle side holes, four nozzle side holes are uniformly distributed in the circumference of the nozzle inner hole and are divergent, an inclination angle alpha is formed between each nozzle side hole and the horizontal direction and ranges from 10 degrees to 25 degrees, the inner wall of each side hole is any radial section of the nozzle inner hole, an obtuse angle is formed between the outer wall of each side hole and the radial section formed by a boundary line of the corresponding side hole in the circumference of the nozzle inner hole and the central axis of the nozzle and ranges from 120 degrees to 135 degrees, the angle between the inner wall of each side hole and the outer wall of the corresponding side hole ranges from 10 degrees to 25 degrees, and the angle between the in