Reconfigurable magnetically actuated soft robots are highly desirable for multi-scenario and multi-task applications due to their variable functions and excellent environmental adaptability. Despite recent progress, existing reconfigurable magnetically actuated soft robots still face the issues with low accuracy of reconfiguration and inability to lock their shapes. Here, an innovative structural design and corresponding preparation process are reported to solve the aforementioned problems. In this work, we present a new type of variable stiffness structure based on the combination of a rigid low-melting-point alloy (LMPA) embedded in elastomer. The use of LMPA as skeletons enables the locking and unlocking of shapes due to its high relative stiffness changes and low or high absolute stiffness states. At the same time, we have implemented a pixelated design that utilizes a combination of magnetic particles and phase change medium as pixel points, with elastomer serving as connections between pixels. Furthermore, in order to meet manufacturing requirements, a multi-material 3D printing technology has been employed to facilitate the integrated manufacturing of the reconfigurable magnetic actuated soft structure. A set of dual-pixel soft robots was designed to demonstrate the feasibility of reprogramming and multi-angle shape locking and unlocking. The resulting reconfigurable magnetically actuated soft machine structure exhibited significant performance, with the ability to achieve locking and precise reconstruction after complex shape deformation. This design effectively broadens the scope of applications for reconfigurable magnetic actuated soft robots.