The present invention discloses a multi-excitation wavelength spectrometer fluorescence laser radar system, including a multi-wavelength laser emission system, a signal frequency division system and a data storage and display system. The present invention emits lasers with a plurality of wavelengths into the atmosphere simultaneously to alternately excite an organic matter in atmospheric particulate matters and obtain a fluorescence spectrum. The lasers with different wavelengths can excite the same organic matter to obtain different spectra. By analyzing a matrix diagram of each excitation and emission fluorescence spectrum, the present invention effectively explores the features of compositions and concentration of the organic matter in the atmospheric particulate matters.