The invention belongs to the technical field of glass production and discloses a method and a device for controlling glass liquid flowing stability in float glass production. The method comprises the following steps of carrying out locking positioning of an end of a molten tin bath close to a lip brick, and arranging a cushion brick at the bottom of the lip brick, wherein the cushion brick is fixedly connected to a furnace. The end of the molten tin bath close to the lip brick is fixed and thus it is guaranteed that the molten tin bath expanded by heating does not move so that a relative location dimension between the molten tin bath and the lip brick is guaranteed. The cushion brick fixed to the furnace is arranged at a lower part of the lip brick and thus the lip brick is fixed and is used as a zero reference point relative to the molten tin bath so that a relative location dimension between the bottom of the lip brick and a backing brick in the molten tin bath is guaranteed. Therefore, the method and the device guarantee the dimensions, and effectively guarantee the stability of a glass liquid flowing through the furnace, a flowing channel, the lip brick and the molten tin bath thereby greatly improving quality of a glass finished product.