Abstract: The half structure calculation model of a five arch greenhouse under wind loading and snow loading was developed. Its structure was optimized, its internal force and stress as well as displacement were gotten with the finiteelement method. The additional wind load and the height changing factor of wind load as well as the shape factor of wind load for multiarch roof coverings, which were not yet mentioned in the current constructional standards, also were analyzed. The results indicate that the structure of this greenhouse is rational, and has fine mechanics properties.