With the help of optical aberration theory, grating dispersion theory and pixel resolution matching theory, we design an initial structure of a wide-spectrum high-resolution grating spectrometer. Based on the comprehensive consideration of the mechanical processing and the efficiency of the spectrometer, this method is applied to the initial structural design of the optical system of a Czerny-Turner grating spectrometer with a wavelength range from 200 nm to 1000 nm and a resolution of 0.01 nm. The ZEMAX software is used to simulate and optimize the optical structure of this spectrometer. The results show that this design method can simultaneously meet various design requirements such as spectral detection range, resolution and clear aperture, so that the instrument design performance can meet the requirements of various indicators.