We developed a tele-operation system for a crane. The crane consists of a large actuator that transports suspended objects and a small actuator that is used as a regulator and feedback-controlled by a wire angle sensor. The operation system can convey the suspended objects safely and efficiently by moving a crane with input signals from screen click interface. However, the suspended object collides with obstacles when dynamic obstacles exist on a conveyance course. Therefore, we propose an algorithm to generate the conveyance course that can avoid dynamic obstacles automatically. The algorithm enables the suspended objects to avoid an obstacle by changing the moving velocity of the suspended objects in the two-dimensional direction that is perpendicular to the gravity direction. We verified the effectiveness of the algorithm through a conveyance experiment.