A casting device for a rolling mill, comprising a base, a lifting assembly, a moving assembly, an adjusting assembly, and a launder assembly connected in sequence, and used as a controller for the operation of the casting device for a rolling mill, the adjusting assembly includes an adjusting bracket, an adjusting rod, and an adjusting weight, The two adjustment brackets are arranged on the moving assembly, the adjustment bracket is provided with a sensing device, the adjustment weight is arranged between the two adjustment brackets, and the sensing device is used to sense the Describe the position of the adjustment weight, the adjustment rod is movably connected with the adjustment bracket and the adjustment weight, one end of the adjustment rod passes through the adjustment bracket and the adjustment weight, and the other end is provided with a tapered plug, and the tapered plug It is installed on the launder assembly to control the opening and flow rate of the launder assembly, the lifting assembly is used to adjust the position of the adjustment bracket in the vertical direction, and the moving assembly is used to adjust the position of the adjustment bracket in the horizontal direction Adjust the position of the adjusting bracket. The adjustment accuracy of the casting device of the rolling mill is more accurate.