Ketosis in dairy cows represents a major challenge confronting China's dairy farming industry, with its high incidence posing a threat to the stable development of the sector. This paper thoroughly explicate the classification, consequences, clinical manifestations, and etiology of ketosis in dairy cows, concurrently engaging in an in-depth exploration of diagnostic technologies. Dairy cow ketosis is categorized into subclinical and clinical forms based on β-hydroxybutyrate levels. The disease exerts profound impacts on cow health, milk production, milk quality, and reproductive performance, thereby escalating operational costs and risks for dairy farms. Its multifarious causes encompass energy metabolic imbalance, periparturient diseases, dietary factors, starvation conditions, and specific nutrient deficiencies, all intimately associated with dysregulations in glucose, lipid, protein metabolism, and hormonal regulation. In the realm of diagnosis, the article present diverse methods, encompassing qualitative detection (ketone powder method, reagent method, test strip method) and quantitative detection (salicylaldehyde colorimetry, spectrophotometry, gas chromatography). This research furnishe a comprehensive knowledge base and technological guidance for the effective prevention and control of ketosis in dairy cows, thereby contributing to enhanced health management and sustainable development within the dairy farming industry.