Abstract: As one of the most common industrial waste gases, the emission of SO₂ may pose a serious threat to the environment and to organisms, and people pay more and more attention to the efficient and portable gas detectors.Compared with traditional detection routes, electrochemical and semiconductor SO₂ gas sensors have been rapidly developed in recent years for their simple structure, easy-operation, excellent performance, and low-cost.The research status at home and abroad of the electrochemical and semiconductor SO₂ gas sensors is presented; the research of device structures, sensitive materials, sensing mechanisms and major technical difficulties in practical application are reviewed, and discuss their development trend in the future.