Economic prediction is the foundation of economic decision-making. Reasonable economic prediction, related to a series of problems such as economic structure and industrial layout, plays an important role in the long-term development of economy. Therefore, the prediction of the economic development trend of Gansu Province in the next few years can provide a decision-making basis for the development of economic development strategy. Based on the establishment of the index system of Gansu Province economic development, the article, referring to the original data, predicts the economic development level of Gansu Province during the 2015-2025 period with DGM (1,1) model. The results show that the DGM(1,1) model can fit the economic development well, that all indexes develop toward the favorable direction, and that the level of economic development increases year by year.