Abstract: Mid-wave infrared is an important detection band. For target detection, the band selection can better distinguish the target and the background in the condition of ensuring a sufficient number of photons. For the mid-wave infrared spectrum characteristic of the representative targets and background, the detection effect of signal-to-noise ratio (SNR) and signal-to-clutter ratio (SCR) was analysed. The band selection method based on synthetic signal-to-noise ratio (SSNR) was proposed. The sensor noise and radiation of backgroud clutter were considered synthetically in this method. The target SNR、SCR and SSNR in some representative conditions were calculated. Simulation results show that the band of high SSNR is different in the different type scenes. The advice of optimization detection band is proposed. In the condition of daytime detection, 3-3.7 m can be considered as a preferred band. In the condition of night detection, 3-5 m can be considered as a preferred band.