In order to obtain spectral response curve of grating dispersive imaging spectrometer for laboratory calibration by back illuminated thinned 1243×576 detector array, a set of spectral calibration device which implements a spectral calibration method with the accuracy of ±1 nm is designed. Factors influencing spectral response including the light source spectral distribution, the grating efficiency, spectral bandwidth of the monochromator, the spectral-line bending and fringes phenomenon are evaluated, and for these confounding factors we propose a mathematical model for calibration. The spectral calibration results show that: the pixel average spectral bandwidth is 2.20 nm, the maximum value of spectral-line bending is 0.925 nm and the bending direction is in line with the theoretical direction. Repeating the test with the mercury lamp, the spectral uncerainty is less than 0.6 nm.