With the rapid development of genetic engineering technology and its widespread application in biological improvement and genetic breeding, the variety of transgenic organisms and their products is gradually increasing. The Cauliflower mosaic virus (CaMV) 35S promoter is one of the most widely used promoters in genetic engineering and is present in various commercialized transgenic crops such as crops, corn, cotton, rapeseed, and tomatoes. Therefore, its safety assessment and detection research on transgenic crops are of great significance. This kit is suitable for detecting the transgenic component pCaMV35S gene in samples and is used to screen whether the sample to be tested contains the pCaMV35S promoter.