The fluorescence sulfur analyzer adopts the principle of "ultraviolet fluorescence method" for measurement. After the sample is introduced into the high-temperature cracking furnace, it undergoes oxidative cracking, and the sulfur in it is quantitatively converted into sulfur dioxide. The reaction gas is dried and dehydrated before entering the fluorescence chamber. In the fluorescent chamber, some sulfur dioxide is converted into excited state sulfur dioxide (SO2 *) after being irradiated by ultraviolet light. When SO2 * transitions to the ground state, photons are emitted, and the photoelectron signal is received and amplified by a photomultiplier tube. After amplification by an amplifier and computer data processing, it can be converted into an electrical signal proportional to the intensity of light. The fluorescence intensity SO2 * generated in the reaction under certain conditions is directly proportional to the amount of sulfur dioxide produced, and the amount of sulfur dioxide is directly proportional to the total sulfur content in the sample. Therefore, the total sulfur content in the sample can be determined by measuring the fluorescence intensity.