Based on the noise suppression effect of weighing measurement principle, a short-wave infrared spectral imaging method based on S-matrix slit array was proposed. By constructing S-matrix slit array to replace the single slit of spectral imaging system, the aliasing measurement of spatial and spectral information was realized. The detector noise and photon noise of the system were analyzed and the noise suppression effect was calculated. The simulation results show that this method can effectively reduce the noise level and improve the imaging quality of low light conditions. The principle prototype was built for imaging experiment. The imaging target was a homogeneous object. By comparing the imaging data onto a single slit, the spectral imaging method of the S-matrix slit array was used to increase the SNR by 9% and 21% respectively under 23% and 10% detector potential well light intensity.