Provided in the present invention are a kit for detecting chronic rhinosinusitis with nasal polyps subtype, and the use of a CST1 gene as a biomarker and a method for detecting chronic rhinosinusitis with nasal polyps subtype. The CST1 gene, as a biomarker, can detect chronic rhinosinusitis with nasal polyps subtype or predict the sensitivity of a patient with chronic rhinosinusitis with nasal polyps to glucocorticoid. The detection method comprises PCR using specific primers of the CST1 gene, such as real-time fluorescence quantitative PCR, so as to detect the expression amount of the CST1 gene.