To address the problem of wavelength calibration of a Brillouin NIR spectrometer with a maximum resolution of 0.1 pm, a calibration process using the principle of collaborative fusion calibration is proposed. This process is based on the idea of gradually reducing the wavelength error of multiple calibrations. The calibration process is as follows: first, the theoretical wavelength was calculated based on the Brillouin spectral analysis modal and relative parameters, such as the pump signal wavelength, Brillouin frequency shift, and gain in spectrum lineshape; then, the relative wavelength was calibrated using the Fabry-Perot etalon; finally, the absolute wavelength calibration based on the gas chamber was completed. The gas chamber was filled with a mixed gas of HCN, ¹²CO, and ¹³CO to achieve absolute wavelength calibration in the C and L bands. A ghost identification and correction algorithm was also presented based on the commensalism of gain and loss spectrum of stimulated Brillouin scattering. Experimental results show that the theoretical wavelength deviation is more than 10 pm, and wavelength uncertainty of ±2.5 pm can be achieved by relative wavelength calibration. Moreover, the wavelength uncertainty of the absolute wavelength calibration is ±0.035 pm.