Abstract: Human factor engineering analysis is a key link in the design process of the main control room of a nuclear power plant. It takes the size data of various parts of human body as the basis for control room layout and equipment design. The comfort and the work efficiency of the operator in the main control room are enhanced. According to the correction method in GB/T 12985-1991 “General rules of using percentiles of the body dimensions for products design” and the requirement of human factor analysis in NUREG-0700 “Human-system interface design review guidelines”, some human body sizes in GB 10000-1988 “Human dimensions of Chinese adults” and GB/T 13547-1992 “Human dimensions in workspaces” have been properly modified in this paper. The upper and lower limits of operator’s body size applicable to engineering design and the body size correction scheme working of the operator who works in the main control room are determined.