Disclosed are a kit for detecting chronic rhinosinusitis with nasal polyps subtype and the use of an ALOX15 gene as a biomarker, and the method for and the use of detecting the expression amount of the ALOX15 gene in cast-off cells in a nasal cavity. The kit comprises specific primers of the ALOX15 gene. The ALOX15 gene, as a biomarker, can be made into a product for detecting chronic rhinosinusitis with nasal polyps subtype. The detection method of the present disclosure comprises the following steps : extracting RNAs from cast-off cells in the nasal cavity, reverse transcribing the total RNA into cDNA, carrying out real-time fluorescence quantitative PCR amplification of the ALOX15 gene and a reference gene of the cDNA respectively with the specific primers of the ALOX15 gene and specific primers of the reference gene by using a quantitative polymerase chain reaction, and calculating the expression amount of the ALOX15 gene based on a detection result of an amplification product.