A spreader pose control system based on the skew angle of the spreader has been implemented by using dual-electric compasses. In the conventional spreader pose control, researchers most often use CCD cameras, laser sensors or tilt sensors to measure the skew angle. However, those sensors are not only sensitive to the weather and disturbances but are also expensive to build a stable system. To overcome these shortcomings, an inexpensive and efficient system to control the spreader pose has been implemented by using dual-magnetic compasses. Note that since the spreader iron-structure itself is a noise source to the magnetic compass, it is not considered prudent to use the magnetic compass to measure the orientation of the spreader. An algorithm to eliminate the interferences of metal structure to the dual compasses has been developed in this paper. To show the effectiveness of the dualmagnetic compasses proposed in this study, a 10:1 reduction model of a spreader control system is implemented and real pose control data are analyzed.