The invention discloses a method for controlling the immersion depth of an immersion nozzle. The method includes the following specific content that after casting of tundish is started, a clamping rodis used for connecting the immersion nozzle preheated to 1000 DEG C with a molten steel outlet in a tundish bottom plate, then a rod body of the clamping rod is placed on a supporting part of the tundish bottom plate, the end, away from the immersion nozzle, of the clamping rod is connected with a mechanical hand adjusting the height of the immersion nozzle, and an upper identification line and alower identification line are arranged on the immersion nozzle. When molten steel of a crystallizer copper pipe enters the immersion nozzle, the molten steel liquid level can be located at the position between the upper identification line and the lower identification line on the immersion nozzle by adjusting the height of the tundish. By means of the method, the immersion depth of the immersionnozzle is determined with the upper identification line/lower identification line of the immersion nozzle adopted as the reference point, the immersion nozzle is fixed to the molten steel outlet in the tundish bottom plate through the mechanical hand and moves along with vertical moving of the tundish, and therefore the required immersion depth can be reached by the immersion nozzle.