Gravity and magnetic data contain information about the density and susceptibility distributions of subsurface rocks and minerals. The physical property distributions are determined by inversion or iterative migration of potential field data. The information in the gravity and magnetic data can complete each other. Therefore, joint interpretation of potential field data can reduce the ambiguity and uncertainty of the information. The iterative migration method is a fast algorithm to recover physical property models from potential field data. This paper introduces a novel joint iterative migration with a focusing stabilizer for potential field data. The joint migration with the focusing stabilizer enforces the structural correlation between migration models because physical properties change rapidly in the same areas. The proposed method is applied to the migration modeling of potential field data from two synthetic examples, and real data from the San Nicolas massive sulfide deposit in Mexico. The joint migration models are more focused and enhance the resolved edges of the geological structures.