Electricity power consumption of a certain city or even a region always has a close relationship with the economic development of the corresponding area. Thus, interpreting the characteristics of previous regional electricity power consumption data as well as past economic data, and finding out the interrelation between them, would be of great reference value in doing the short-term forecasting work together for both. The combined forecasting work will undoubtedly be more rational and accurate in giving future electricity power consumption tendency, by comparing with the work merely based on electricity power consumption data itself. Till now, most related research have focused on analyzing the mutual relationship between electricity power consumption and economic development, forecasting work based on both aspects can still hardly be found. In this paper, a short-term forecasting approach for regional electricity power consumption by considering its co-movement with economic indices has been proposed, it has fully considered the interaction between electricity power consumption and the economic indices, and has let the forecasting result of latter make the "secondary correction" to the result of former. By setting a certain region in central western China as an example, the effectiveness of proposed approach has been proved.