Abstract: An HPLC method was developed to separate cannabidiol (CBD) and its forced degradation products under acidic, alkaline, oxidative, and thermal conditions, with identification by LC-MS/MS. The separation was conducted on Hedera ODS-2 C18 column by gradient elution using 10 mmol/L sodium dihydrogen phosphate buffer and acetonitrile as mobile phases; identification was performed using 0.1% formic acid in water and acetonitrile as mobile phases under positive ESI mode with a triple quadrupole MS. Eighteen related substances were detected, with the highest number and abundance occurring at 80℃. Nine major products (≥0.1%) were identified and categorized as cannabichromene-, cannabinol-, cannabielsoin-, cannabinodiol-, cannabigerol-, and tetrahydrocannabinol-type compounds. The methods effectively characterized CBD degradation products, supporting quality control and process optimization.