Large plant construction has numerous works, and the proportion of hoisting operations in the total construction work is high. In the hoisting operations, many things should be considered to keep the operations safe, and the work steps of the hoisting operations are planned by considering them. However, it is difficult for novice construction workers to understand the work steps with conventional two-dimensional drawings. Thus, to have those workers understand it well, we developed the hoisting-operation simulator considering the physical behavior of a load in conjunction with 3D viewer and physics engine. The simulator can visualize the work steps as three-dimensional animation. Moreover, by associating the simulator with mixed reality technology, we developed the system superimposing the 3D animation on reality space via head mount display. Experiments verify that the 3D animation of a load moves with the vibration due to the inertial force and that the 3D animation generated by the simulator is superimposed in the work site.