Slab tundish casting method and device

The embodiment of the invention provides a slab tundish casting method and device. The slab tundish casting method comprises the steps that casting condition judgment is started; when the casting conditions meet the preset conditions, in the first time period, a tundish trolley is controlled to move a tundish to a first casting limit position; in the second time period, the tundish trolley is controlled to descend, and a weighing system of the tundish is reset in the process that the tundish trolley descends to the second pouring limit position; in the third time period, the large ladle of molten steel is injected into the tundish, and the weighing system is started to monitor the weight of the tundish; when the weight of the tundish reaches the preset weight, a stopper rod of the tundish is opened, and the molten steel liquid level of a crystallizer is monitored; when the liquid level of the molten steel reaches the preset height, a withdrawal and straightening machine is started at the initial speed; and th