The utility model discloses a tundish slide gate nozzle mechanism which comprises an upper slide plate framework, an upper slide plate, a lower slide plate framework, a lower slide plate, a middle slide plate framework, a middle slide plate, a compression spring, a central hole and two check blocks, wherein the upper slide plate is fixedly arranged in the upper slide plate framework; the lower slide plate is fixedly arranged in the lower slide plate framework; the middle slide plate is fixedly arranged in the middle slide plate framework; the middle slide plate can slide forth and back along with the middle slide plate framework along a slide slot arranged on the lower slide plate framework; the upper slide plate framework and the lower slide plate framework are fixedly connected through a bolt; the compression spring is used for positioning the upper slide plate framework and the lower slide plate framework in the vertical direction; the central hole vertically penetrates the tundish slide gate nozzle mechanism and is communicated with a nozzle, and the nozzle is fixedly connected with the lower slide plate framework; and the two check blocks are fixedly arranged below the upper slide plate framework and respectively blocked behind the left end and the right end of the tail part of the lower slide plate framework.