In view of the limitations of traditional air combat situation assessment method,which only considers the current static situation,is difficult to evaluate the whole air combat situation and has no predictability,a situation assessment method based on improved MGM(1,N) trajectory prediction is proposed.Firstly,according to the deficiency of MGM(1,N) prediction model which is difficult to describe the linear relationship between variables,an improved MGM(1,N) prediction model is established based on background value optimization.Then,the air combat situation preponderance model based on non-parametric method is established to quantitatively describe the influencing factors of air combat situation.The weight of each index is calculated by grey correlation degree,and the method for calculating the sequential weights of multiple moments are considered and established.The result of the simulation to actual air combat data shows that,the prediction accuracy of this method is better than that of the traditional MGM(1,N) method.The situation evaluation results can not only accurately reflect the battlefield situation,but also effectively reflect the changing tendency of air combat situation,with good predictability.