Abstract: NH₃ emissions have a serious threat to the atmospheric environment and human health. In recent years, the efficient real-time detection of NH₃ has become a research focus in the field of environmental monitoring and analytical chemistry. Graphene, as a typical two-dimensional (2D) nanomaterial, provides a good platform for gas detection due to its unique physical and chemical properties. Graphene and graphene-based composites have been widely used in the detection of NH₃ gas. The research progresses of NH₃ gas sensors based on the graphene-based composites in recent 10 years have been reviewed in this paper. Compared with pristine graphene, the adsorption capacity of NH₃ gas can be enhanced by metal particle doped grapheme; metal oxide-doped graphene can effectively improve the sensitivity of NH₃ gas sensing, but with a long response time and poor repetition; organic polymer-doped graphene has relatively poor stability and high environmental requirements; graphene ternary composite materials can effectively improve the stability of the sensor and improve the sensor selectivity. Finally, the future development trends of NH₃ gas sensor are briefly proposed.