Abstract: In this paper, the exponential smoothing method was used to analyze the basic occurrence of four main diseases of apple, Valsa mali, Botryosphaeria berengeriana, Marssonina mali and Alternaria mali from 2000 to 2019 in Gansu Province.The actual occurrence data for the four diseases in 2020 were used for the verification.The occurrence trend of the four disease from 2021-2022 was predicted and the correlation between the occurrence degree and the occurrence area was analyzed.The results showed that the fitted values of the four major diseases were quite close to the actual value in 2020, and an upward trend of occurrence in Gansu Province from 2021 to 2022 for the four diseases was predicted.Among them, the incidence of apple tree Valsa mali would be light, while the other three diseases would be occurred with rapid upward trends.Disease prevention and control was required to be strengthened.Correlation analysis showed that there was no correlation between the occurrence degree and the occurrence area of the four major apple diseases in Gansu Province.This study provided a theoretical basis for short-term apple diseases prediction.