There are two important characteristics for missile plume in infrared multispectral imagery: one is the gray-scale difference caused by strong infrared radiance; and the other one is the unique spectral signature feature. However, the classical single-band detection technology only uses the first characteristic, and the multispectral detection technology which has been developed in recent years only uses the second characteristic. In order to fully exploit the characteristics of missile plume, three detection algorithms were proposed by combining the single-band and multispectral detection technology. The advantages and disadvantages of the three algorithms were discussed in detail in the aspects of detection performance, computational complexity and robustness. Experiments on synthetic infrared multispectral imagery demonstrate a better performance of the combined algorithms when compared with single-band or multispectral detection algorithm.