Spectral calibration must be carried out in order to determine its central wavelength and half-wave band width of each pixel before the usage of imaging spectrometer. But it was found out that these parameters vary as environment changes. The present paper studies the effect based on test field data. The authors analyzed the optical structure and compared the working environmental parameters. Then a theoretical model is established and the influences of vibration, distortion and temperature parameters are evaluated. The theoretical model and the caculation results are in good consistency, which testifies the theoretical model. This research will shed some light on the high accuracy spectral calibration of the grating based imaging spectrometer and its manufacture.