As a kind of production equipment, CNC machine tools safety is very important. As a result of the technology index of processing improving, a series of security issues were brought in, such as some threats to the security of machine tools and personnel due to collision, tool breakage, out of control and etc., during the manufacturing process, and the pollution to environment. Aimed at these problems, from three aspects in separate as the safety of CNC machine tools, the safety of operator and environmental protection, safety problems existed in the machine tools were analyzed. By taking the principles of safety, ergonomics and psychology, and other theories as the instruction, the current research situation of CNC machine tool safety at home and abroad was analyzed. The direction of development of CNC machine tool safety was put forward.