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There are many NOx pollution control technologies under investigation, which can be classified into three main categories from a methodological perspective: (1) Chemical methods: SNCR, SCR, direct decomposition method； (2) Physical sciences: High-pressure electron beam technology, low-temperature non-equilibrium plasma technology ； And (3) biological methods: microbial denitrification of flue gas, etc. In practical industrial applications, the two main technologies that are currently widely adopted are combustion control NOx reduction technologies and flue gas denitration technologies. Combustion control NOx technologies control the amount of NOx generated by optimizing combustion, and mainly include techniques such as Low NOx burners (LNB), staged combustion, and reburning. The selective NOx removal method is the one that is most commonly used in flue gas denitration technologies; this method involves injecting nitrogen-containing chemicals into the flue gas, where they react with NOx to produce pollution-free nitrogen and water. When a catalyst is used in selective NOx removal methods, this method is known as Selective Catalytic Reduction (SCR). Correspondingly, if no catalyst is used, this method is called selective non-catalytic reduction (SNCR). Generally speaking, combustion control NOx technologies have low installation and operation costs, but their denitration efficiency is relatively low, typically around 30%. Flue gas denitration methods have high installation and operation costs, but they offer high denitration efficiency. Due to the use of a catalyst, SCR can achieve a higher denitration rate than SNCR (the denitration rate of SCR can exceed 90%, while SNCR generally achieves a denitration efficiency of 40%–50% in industrial applications); however, the operating costs of SCR are also much higher than those of SNCR. Therefore, based on the comprehensive optimal principle of cost and utility, NOx control technologies through combustion should be given priority