Sulfuryl fluoride (SO₂F₂) is a representative early decomposition product of SF₆, and accurate quantitative analysis of SO₂F₂ 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 SO₂F₂ is of great importance. To this end, a highly sensitive SO₂F₂ gas photoacoustic sensor system for SO₂F₂ 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 SO₂F₂ for the first time in the side peak absorption band at a central wavelength of 1511 cm^-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.