Air freight is an important part of modern transportation logistics system. In recent years, with the continuous development of air freight industry, the freight volume has continued to grow. Therefore, accurate prediction of air freight volume is very important for the development and operation of air transport industry. In order to scientifically predict the air cargo business volume between cities and comprehensively consider the influencing factors such as the level of urban economic development and airport facilities, the grey forecasting model was used to predict the total cargo business volume of airports, and then the comprehensive service capacity score of urban airports and the freight attraction intensity between urban nodes were determined by using principal component analysis and improved gravity model, so as to judge the trend of cargo flow. Finally, the freight volume between urban airports in 2026 was obtained by constructing a combined forecasting model. The results show that China’s air freight business market is in a period of rapid development, and the forecast of freight volume has certain reference value for setting the operating capacity of freight airports and improving the support capacity of logistics facilities.