A self-moving device and a control method for a self-moving device are disclosed. The self-moving device includes a moving module, a control module and an adjusting device. The moving module includes a track, driven by a drive motor to drive the self-moving device to move. The control module controls the adjusting device to adjust a grounding length of the track, such that the grounding length of the track when the self-moving device turns is smaller than that of the track when the self-moving device moves straightly. The control method for a self-moving device includes the steps: controlling to reduce the grounding length of the track before the self-moving device is controlled to turn; and controlling to increase the grounding length of the track after the self-moving device is controlled to finish the turning. In the self-moving device, since the grounding length of the track during turning is smaller, a contact area between the track and a lawn is smaller, the damage of the track to the lawn can be reduce
