With the increasing prominence of pollution problems in iron and steel industry and the sharp tightening of environmental protection emission standards, the denitration of sintering flue gas has become the focus and difficulty of pollution control in iron and steel industry. Activated carbon denitration has the advantage of safety, stability, sulfur resistance, water resistance, and low requirements for flue gas temperature, and it is a low-temperature denitration technology with great application prospects. Aiming at the problem of large fluctuation of sintering flue gas and difficult process control, the effects of O₂ volume fraction, humidity, inlet NO volume fraction, airspeed and ammonia/nitrogen molar ratio on activated carbon denitration are studied, and the test parameters of denitration rate in GB/T 30202—2013 and GB/T 35254—2017 are compared and analyzed. The results show that NH₃-SCR is the main source of activated carbon denitration, and the contribution ratio of physical adsorption denitration is 29.1%. The denitration rate of activated carbon is affected by the change of flue gas conditions significantly, and the volume fraction of O₂, the volume fraction of NO, and the molar ratio of ammonia/nitrogen are positively correlated with the denitration rate, while humidity and airspeed are negatively correlated with denitration rate. In addition, it is recommended to take the average denitration rate of 5 h at the end of the reaction as the test value of GB/T 35254—2017.