Surface acoustic wave (SAW) gas sensing technology has the characteristics of high sensitivity, fast response, miniaturization and lightweight because of its unique acoustic sensing structure and force-acoustic-electric physical field coupling sensing mechanism, which makes it gradually become one of the emerging gas sensing technologies that people pay close attention to. Based on the SAW propagation and sensing theory, this paper introduces in detail the research progress of SAW gas sensing effect and mechanism, sensor device design and preparation, sensor signal acquisition and processing, etc. Besides, the potential application of SAW gas sensors in many fields such as new energy, aerospace, national defense, industrial control and intelligent manufacturing and its development trend are discussed.