It has been an aim devoted to seeking a kind of economical and effective catalyst used in super-cooled cloud in the field of weather modification. Nano-catalyst becomes thus the first goal. The number of ice crystal nucleus, operation effectiveness and ability can be enhanced by preparing nano-catalyst with similar structure to ice crystal because of its size effect, volume and surface effects. This becomes possible to use it as a kind of high efficient and low cost catalyst in weather modification. The application prospect of nano-catalyst in weather modification is discussed through theoretical analysis and preliminary experiments according to its nature and characteristics.