A control method for a construction machine includes: generating a target value of an amount of control of each of a tilt bucket and a swing body, based on operation data obtained when working equipment and the swing body are operated and a design surface indicating a target shape of a construction target; calculating a predicted value of the amount of control of each of the tilt bucket and the swing body, based on the target values and a prediction model for the construction machine; calculating amounts of drive to control the working equipment and the swing body, based on the predicted values and the design surface to maintain a distance from the tilt bucket to the design surface and an attitude of the tilt bucket; and outputting control commands to control the working equipment and the swing body based on the amounts of drive.