▎ 摘　　要

Development of gas sensors for detecting toxic, harmful, flammable, and explosive gases has always been very popular research direction. Graphene is considered potential chemi-resistive gas sensing material owing to its high specific surface area and good conductivity. Recent studies have shown that graphene-based gas sensors doped with metals, polymers, and metal oxides have good sensitivity, selectivity, and repeatability. Moreover, they are superior to traditional gas sensors. In this review, sensing mechanism of such composite sensors is introduced. In addition, research status on various sensors is discussed, and their advantages and disadvantages are summarized. Possible improvement methods are proposed as well. Finally, several common problems characteristic of graphene-based gas sensors are described, together with some critical ideas for improving their performance.