An embodiment of the invention provides a method and a device for reducing potential injury to operators. The potential injury to the operators is caused by intersections among hazardous portions of a workpiece gripped by a robot and the physical portions of the operators, and the physical portions of the operators are located in a working zone of the robot. The method includes selecting first, second, third and fourth values for first, second, third and fourth variables; predicting degrees of the potential injury to the operators due to the intersections among the hazardous portions of the workpiece gripped by the robot and the physical portions of the operators according to the selected first, second, third and fourth values. The relative speeds of the hazardous portions of the workpiece and the physical portions of the operators are expressed by the first variables, inertia degrees of the robot and the workpiece are expressed by the second variables, vulnerable degrees of the physical portions of the operators are expressed by the third variables, and hazardous degrees of the hazardous portions of the workpiece are expressed by the fourth variables. The physical portions of the operators are located in the working zone of the robot.