In this study, we propose an adaptive band selection method based on the spectral measurement data, considering the interference of background radiation and instrument noise on target detection. Further, an acousto-optic tunable filter imaging spectrometer is used to collect the spectral data with a spectral scanning band of 400-1000 nm. An unmanned aerial vehicle target and a static object are detected against a sky background and a wall background, respectively. The integrated signal-to-noise ratio of each wavelength is calculated to be 0.7 times the maximum value and is set as the threshold for selecting an appropriate working band. The band selection result is in accordance with the actual situation. The experimental results demonstrate that the proposed method can effectively select optimal detection bands for different targets.