Sulfuryl fluoride(SO2F2)is a representative early decomposition product of SF6,and accurate quantitative analysis of SO2F2 can effectively predict potential faults in electrical equipment,thereby preventing equipment damage and maintaining the safe and stable operation of the power system.Therefore,the rapid and highly sensitive detection of SO2F2 is of great importance.To this end,a highly sensitive SO2F2 gas photoacoustic sensor system for SO2F2 gas based on the mid infrared wavelength band is developed,which combines a miniature resonant photoacoustic cell with a QCL laser,enabling high sensitivity photoacoustic detection of SO2F2 for the first time in the side peak absorption band at a central wavelength of 1511cm -1.The results show that the photoacoustic system has a responsivity of 63.32 mV/ppm and a minimum detection limit of up to 1.7 ppb when the integration time is 13s.