We presents a high-payload climbing robot based on a compliant track-wheel mechanism. The compliant track-wheel mechanism changes the configuration of the robot according to the conditions of the external structures without feedback control; and the robot can perform 90-degree wall-to-wall internal and 240-degree wall-to-wall external transitions. Segmented magnets on the track-wheel are used to attach onto steel walls. The large contact area of the magnets achieves a relatively high-payload capacity of 3 kg compared to the robot mass of 4 kg. The parametric design based on kinematics and statics was developed to guarantee stable climbing. Experimental verification of the payloads and the transitions are presented. We expect that the robot can be applied to move heavy materials to high places in shipbuilding and plant industries.