A new combination invariants method is proposed for aircraft recognition.For all kinds of aircraft types,Hu moments,affine moments and normalized Fourier descriptors are extracted and combined.As the above invariants are too dispersed,four kinds of normalized methods are studied and combined with support vector machine(SVM) to improve aircraft classification performance.Simulation results show that the classification performance is better by the combination invariants which are combined with support vector machine classifier or neuron network than that by any single kind of invariants which are combined with corresponding classifiers,and the classification performance is better by support vector machine classifier than that by traditional neuron network classifier.Moreover,when combination invariants are sent to intelligent classifiers,a special normalization method can improve the classification performance.