Abstract: The Uncertainty of the prediction factors which influenced the crop yield under natural conditions was one of the key issues which determined the veracity of the crop yield prediction.Based on set pair analysis and aimed at the characteristics of crop yield prediction,the crop yield prediction model was built.The prediction factors were divided into four categories,such as feasible,not significant influencing,not feasible and yield reduction,by introducing the connection degree.Taken the wheat yield prediction in Xinchang County as an example,the prediction model was validated.The results showed that the feasibility of the prediction factors and the accuracy of the wheat yield prediction were improved by using connection degree.

Key words: Crop yield prediction, Crop yield prediction, Uncertainty, Set pair analysis, Connection degree