In this cast strip manufacturing method, in a first step, one end side and another end side in a rotation axis direction of a pair of cooling drums are pressed with a first pressure in a direction in which the cooling drums come close to each other, in a second step, the one end side and the another end side in the rotation axis direction of the cooling drums are pressed with a second pressure, which is higher than the first pressure, in the direction in which the cooling drums come close to each other, and in a third step, pressure control is performed so that a total value of reaction forces on the one end side and the another end side in the rotation axis direction of the cooling drums is set to a predetermined value, and rotation axes of the cooling drums are held in parallel.