In order to solve the problem of per capita GDP forecasting in Anhui province, taking the per capita GDP data of Anhui province from 2000 to 2018 as the research sample, where the data from 2000 to 2017 are used as the training set and the data in 2018 as the testing set, a new forecasting evaluation index -- adjacent degree and combination forecasting model based on adjacent degree was proposed, and a new combination weights coefficient solution method was introduced. First, the data is used to do three kinds of single forecasting, which is the exponential forecasting, parabolic forecasting and moving average forecasting. Next, three kinds of single forecasting models are considered comprehensively, constructing a weighted geometric average combination forecasting model based on adjacent degrees. The combination forecasting model is solved, then the weights of every single forecasting are obtained， and the combination forecasting value based on adjacent degree is received. Finally, comparing with other forecasting models in training set and testing set， 2019—2021 per capita GDP data in Anhui province is forecasted.