Stereoscopic imagers are widely used tools for precise three-dimensional (3D) characterization of various objects in industrial and biomedical applications. Narrow-band spectral imaging significantly increases capabilities of these devices, i.e. allows to analyze spatial distribution of spectral properties as well as to achieve higher image contrast, lower optical aberrations and, therefore, to improve geometrical measurements accuracy. Using spectral stereoscopic images for 3D measurements requires a proper choice of a number, positions and width of spectral bands used for calibration and interpolation of the calculated parameters. The experimental determination of these parameters does not guarantee the optimal choice and may be difficult to implement and time-consuming for a large number of spectral bands. In this paper, we demonstrate that the optical design software can be effective for the computer simulation of calibration, comparison of mathematical models and assigning spectral calibration parameters. We show the possibility to optimize the parameters of multi-spectral geometrical calibration to ensure the required measurement accuracy provided by the stereoscopic system on the stage of its optical design before manufacturing via the design of self-developed prism-based imager. Computer simulation allowed us to compare two camera models and various spectral options (conventional white-light as well as arbitrary number, positions and width of spectral channels) applied to calibration procedure. The results of computer simulation are confirmed by multiple experiments. Proposed approach may be used for estimation of 3D measurements errors caused by image noise, tolerances of optical components, temperature variations and other factors.