The color grade, mainly introduced in the processes of semisynthesis and storage, is an important index used to evaluate the quality of cefotaxime sodium. Because the drug itself is prone to degradation under susceptible conditions, including those involving moisture, heat, ultraviolet light, acids, alkalis, and oxidants, and a series of degradation products as impurities are generated. In this study, the factors affecting color grade stability and the degradation mechanisms of cefotaxime sodium were investigated by designing different accelerated stability tests under the aforementioned conditions. The degradation extent was studied by using analytical methods, such as a solution color comparison method, ultraviolet spectrophotometry, and HPLC. The relationship between the color grade stability of cefotaxime sodium and its impurity profile has been explored, and a reasonable degradation mechanism has been proposed. The manufacturing conditions of inspection have been optimized, and a scientific basis for drug packaging, storage, and transportation conditions has been established. The results show that the color grade stability of cefotaxime sodium is related to the impurity profile to some degree, and the difference between the actual color and the standard color can reflect the levels of impurities to some extent.