In order to precisely calibrate the center wavelength and bandwidth of 1024×80 spectral pixels of a prism-dispersive hyperspectral imager, a spectral calibration facility is established, and a spectral calibration method to realize 1 nm wavelength accuracy is presented.Firstly, the spectral line bend and spectral line tilt are introduced, and the precise spectral calibration method and data processing algorithms are determined. After the discrete monochrome response values of all spectral pixels are measured with the spectral calibration facility, the relative spectral response curves are fitted with Gauss function. Finally,the center wavelength matrix and bandwidth matrix are established,the dispersive equations of different spatial pixels and the spectral line bend equations of different spectral channels are given with a polynomial fitting,and the spectral line deviation with circumstance temperature variation is experimentally measured. Furthermore,the effect of spectral calibration accuracy on the radio metric calibration accuracy is discussed.Experimental results indicate that the spectral calibration accuracy reaches 1 nm,and the average bandwidth of all pixels is 8.75 nm. The dispersive equation and the spectral line bend are coincident with design values well,in which the spectral line bend value is between 14 and 19 nm and the average is 17 nm.Moreover,the 1 nm center wavelength accuracy can cause less than 1% radiometric calibration deviation for a 3 000 K blackbody calibration source, and 0.25% for a 6 000 K blackbody calibration source.These results can satisfy the spectral calibration requirements of 1 nm wavelength accuracy.