Abstract: Ammonia, as a carbon-free fuel, has attracted considerable attention in the low-carbon energy transition. However, high NO_x emissions during combustion constrain its industrial application. Wet combustion technology introduces steam into the combustion zone to lower the flame temperature and optimize nitrogen-conversion pathways. It can effectively suppress NO_x formation while increasing the mass flow rate of the working fluid to improve the efficiency of power-generation systems, representing a promising technological pathway for addressing NO_x emission challenges. This review summarizes recent advances in wet ammonia combustion from three aspects: combustion systems, combustion technologies, and chemical kinetics, and also discusses future perspectives. The wet ammonia combustion systems developed so far mainly include steam injection (STIG), chemical recuperation and humidified combined cycle technology (CHGT), and humidified rich-burn ammonia-hydrogen gas turbines, with power ratings ranging from the kilowatt-scale to the megawatt-scale. In the pure ammonia-fueled micro-gas turbine, the STIG cycle can improve electrical efficiency by 15%. In the CHGT cycle, partially cracked ammonia can achieve a net electrical efficiency of 56.7%, which is 20.6 percentage points higher than that of the dry Brayton cycle in absolute terms and comparable to that of conventional natural gas combined cycles. Deep integration of wet ammonia-fired power systems with oxy-fuel combustion technology is expected to further overcome efficiency bottlenecks. Wet ammonia combustor structures mainly adopt swirl combustion technology, which can be synergistically combined with MILD (moderate or intense low-oxygen dilution) combustion and RQL (rich-quench-lean) staged combustion to regulate NO_x formation and reduce NO_x emissions to relatively low levels. Combined with partial ammonia cracking and steam dilution, both NO_x and NH₃ emissions can be kept below 100 ppm under near-stoichiometric conditions, and even near-zero NO emissions can be achieved. Currently, wet ammonia combustion technology has been experimentally validated at the 10-kW scale. To further increase power ratings and improve stability under high steam dilution conditions, future efforts could focus on promoting the application of wet ammonia combustion technology in porous-media burners. Kinetic studies have mainly focused on the effects of steam dilution on flame-propagation characteristics and NO_x emissions in pure ammonia, hydrogen-blended ammonia, and carbon-based fuel-blended ammonia. Steam dilution generally reduces the laminar flame speed but has no significant effect on the equivalence ratio at which the peak flame speed occurs. The temperature regime affects the inhibitory effect of steam dilution on NO emissions, and water addition may promote NO generation at intermediate-to-high temperatures. Decoupling the physical and chemical effects of water vapor is key to a deeper understanding of the mechanisms of steam dilution, with physical effects playing a dominant role. Kinetic models applicable to wet conditions currently focus on laminar flame speed and species distribution during oxidation at intermediate-to-low temperatures. Future work needs to extend the applicable temperature and pressure ranges of kinetic models, and improve ignition delay-time measurements and model optimization.