A novel short infrared multichannel integrated spectrum assembly (MISA) worked in the range of 1355~1555 nm is reported. The influence of the incident angle on the center wavelength of each channel and the resolution of MISA is quantitatively studied in a theoretical and experimental manner. The experimental results show that the center wavelength of each channel of the spectroscopy component exhibits different degrees of short-wave direction shifting at 0~10° oblique incidence, and the degree of deviation is positively correlated with the incident angle. The theoretical and experimental center wavelength offset curves are plotted, and the experimental results show that the average shift amplitudes of the center wavelength at the incident angles of 5° and 10° are approximately 5.7 nm and 1867 nm, respectively. In addition, by referring to the experimental angle deviation curve, the spectrum was interpolated and integrated at two different incident angles, and the resolution of the spectral components was successfully increased from 7.5 nm to 3 nm. Based on this experiment, we proposed a multi-channel angular tuning spectral assembly by changing the incident angle, and then using this method to improve the test resolution of the spectral components. This conclusion has certain guiding significance for designing the incident optical system and improving the test resolution of MISA.