Abstract: At present, there is a very huge gap between home and abroad for the development of astronomic instrumentation technologies. In some regions such as telescope instrumentation with super large mirrors as long as advanced imaging spectrometers, there exists a gap of generation. In this presentation, a general introduction of principles that have to be obeyed in optics design will be provided by analyzing some typical designs of telescopic instrumentation at home and abroad. Besides, the general rules of thumb for optics system instrumentation will also be concluded in the presentation. These will cover the general topics such as tolerance analysis, stray light analysis, and so on.