The spaceborne limb imaging spectrometer (LIS) operates in a sun-synchronous orbit and uses limb scanning to detect oxygen A-band airglow. Due to the strong absorption of oxygen, it is difficult to observe airglow emission from the ground, which limits the LIS's detection capability. Therefore, the spectral simulation method is discussed in this paper. Firstly, we obtain the LIS's working parameters, including a track altitude of 520 km, a scanning altitude of 10~100 km, and a scanning interval of 2 km. Secondly, based on laboratory calibration, spectral and radiation response parameters were obtained. The spectral calibration matched the lamp peaks and pixels. The polynomial fitting results show that the spectral range of LIS is 498.1~802.3 nm, with a spectral resolution of 1.38 nm obtained by Gaussian fitting. For radiometric calibration, the radiometric relative deviation at different pointing angles is ±0.5%. The least squares method was used to fit the radiance and response Digital Number (DN) values to obtain the radiation calibration coefficients for all integration times (ranging from 25 ms to 3 200 ms) with a radiation calibration uncertainty of 3.6%. Based on the airglow transmission length, the Mass Spectrometer and Incoherent Scatter(MSIS) model, and High-resolution Transmission molecular Absorption(HITRAN) database,the airglow transmittance is calculated. The results show that airglow transmittance is less affected by oxygen absorption above 80 km, with a transmittance of 0.9, and stronger oxygen absorption at 60 km, with a transmittance of less than 0.05. Based on the airglow observed by the Scanning Imaging Absorption spectrometer for Atmospheric CHartographY (SCIAMACHY), the onion-peeling method was used to obtain the volume emission rates, and then high-resolution airglow emissions were calculated, which vary at different target heights. Finally, the high-resolution airglow emission convolved with the response function, combined with the calibrated radiation response coefficient, yields the DN value of the airglow response of LIS. The results show that LIS can effectively detect airglow emission, and the spectral shape can characterize its temperature dependence. LIS has a good signal-to-noise ratio at the longest exposure time of 3.2 seconds. Through this simulation, the airglow detection capability and inversion algorithm of imaging spectrometers can be evaluated, providing scientific support for the exploration of the middle and upper atmosphere.