Atmospheric absorption is one of the significant factors influencing the atmospheric propagation efficiency of high-power fiber lasers. Based on typical atmospheric environment parameters, the atmospheric absorption (aerosol and atmospheric molecular absorption) of fiber lasers with different linewidths and center wavelengths in a near 1 µm band is numerically calculated. The results show that the atmospheric absorption of common (several nanometer scales) and narrow linewidth (<1n m scale) lasers have distinctly different external characteristics, but the intrinsic mechanisms are interconnected. Due to the high wavelength selectivity of atmospheric molecular absorption, this work focuses on the factors influencing water vapor (main absorbing gas) absorption of different linewidth lasers and the corresponding low absorption region. Based on the fine atmospheric absorption spectra of different types of fiber lasers, the output spectra of fiber lasers can be artificially designed to avoid strong absorption during atmospheric propagation and achieve improved high-energy laser propagation efficiency. The above method provides a partial reference for designing and optimizing the light source parameters of high-power fiber lasers for atmospheric propagation.