The significance of the robots in the medical field have been increasing rapidly. Humans and robots working together increases the strengths and decreases the limitations of surgical operations. Human life makes safety the most important problem for medical robots, for which there are no universal standards. This paper presents detailed design methods for increasing medical robots' safety by considering issues of sterilization, robot's size, operating room placement of the robot, the robot mechanics, selection of the electromechanical components, drive mechanism, stiffness, sensor redundancy, software application, and hazard identification and analysis. The proposed safety design concepts were put into practice on a surgical robot prototype and the outcomes are discussed.