Abstract: To estimate the economic benefit of the China satellite application industry under the lack of statistics,the similarity system theory is adopted,which transforms the U.S.satellite application industry system into the China satellite application industry similarity system and estimates the economic benefit of the China satellite application industry based on the U.S.data.Then the results are verified through principal component analysis.The research demonstrates that the similarity system theory is a logical and feasible theory of forecast model,which can resolve not only the problem about the lack of data,but also the actual problems of forecast,decision making and programming in which it is difficult to construct mathematical models directly.