The invention discloses a method for inversing the vertical column concentration of carbon dioxide in environmental atmosphere by utilizing direct-radiation solar spectrum. The method comprises: performing first-order Taylor expansion on obtained direct-radiation solar spectrum to obtain linear superposition of solar normalization radiance, a column weight function of carbon dioxide and other interference factors, and a low-order polynomial; then utilizing an atmosphere radiation transmission model SCIATRAN to model the solar spectrum; and performing non-linear least squares fitting on an analog computation value and the direct-radiation solar spectrum, so as to derive the vertical column concentration of carbon dioxide. In the modeling process, observation physical parameters corresponding to recorded solar spectrum, instrument functions corresponding to the spectrum resolution of a spectrum detection system, a priori carbon dioxide profile and a priori interference factor profile, and aerosphere height and atmosphere sublayer quantity are detailedly considered, and the temperature and pressure intensity dependence characteristics of an infrared-band gas absorption cross section are effectively corrected; and by employing the method, the fluctuation rule of the vertical column concentration of carbon dioxide in environmental atmosphere can be accurately mastered.