Creating the realistical sky scene has very important application value in simulation environment and weather phenomenon. It is also a difficult task within computer visualization study. An algorithm that can generate colorful and realistic sky scenes is described. The algorithm includes the following procedures: to create the basic cloud picture by determining the color hierarchy mode and improving the midpointed position shifting method; to conduct cloud picture mapping based on images; to create the sky scene in combination with meteorological elements through optical superposition, background synthesis, and color modification, etc. It can play an important role in various kinds of meteorological phenomenon simulation and the development of weather information visual system.