Abstract: In order to investigate the effects of water-fertilizer-gas coupled drip irrigation on processing tomato yield, quality and CO₂ emissions from processing tomato land, and to screen out better treatments that take into account high yield and quality, reduce greenhouse gas emissions and improve economic efficiency. This study was conducted in a 4-month field trial in 2023 at the Key Laboratory of Modern Water-saving Irrigation, Shihezi University, Shihezi City, Xinjiang. This experiment was a three-factor completely randomised trial using irrigation level, humic acid addition and aerating method, and the local conventional irrigation level was 4500 m³/hm² , so the irrigation level was set at 4500 m³/hm² (W2) and 3800 m³/hm² (W1), humic acid addition was set at three levels, 0% (H0), 0.25% (H1) and 0.5% (H2), and the aerating method was conventional sub-film drip (A0) and micro-nano aerated drip (A1), to study the effects of water-fertilizer-gas coupling on the yield, quality, GHG emissions, and net profit of processing tomatoes. The results showed that, in terms of carbon emission and carbon sequestration, the cumulative CO₂ emission flux, initial carbon productivity and net carbon sequestration under W2 treatment were significantly increased by 17.14%, 23.91% and 25.36%, respectively, compared with W1 treatment; and the indicators of each index under H2 treatment were significantly increased by 12.23%, 11.48%, and 12.26%, respectively, compared with H1 treatment, and by 24.59%, 26.47%, 25.18%, 24.59%, 24.59%, 26.47%, and 25.18%, respectively, compared with H0 treatment, 26.47% and 25.18%, respectively; H1 treatment was significantly larger than H0 by 11.02%, 12.29% and 12.66%, respectively; and the indicators of A1 treatment were significantly larger than those of A0 by 12.28%, 13.02% and 12.64%, respectively. In terms of yield quality, processing tomato yield, number of fruits, quality of single fruit and IWUE were significantly increased by 19.87%, 9.98%, 8.86% and 17.30% (P＜0.05) in the W2 treatment compared to the W1 treatment, but vitamin C, soluble sugar, titratable acid, soluble solids, and lycopene content of processing tomatoes were significantly reduced by 14.58%, 7.99%, 10.18%, 4.77%, and 12.89% (P＜0.05).Tomato yield, number of fruits, quality of single fruit, IWUE, vitamin C, soluble sugar, soluble solids, and lycopene were increased by 15.86%, 5.25%, 10.59%, and 15.63%, 29.32%, and 10.91%, respectively, in H2 treatment compared with H0 treatment, 6.92%, 26.03% (P＜0.05).Tomato yield, number of fruits, quality of single fruit, IWUE, and vitamin C were significantly improved in H2 treatment compared to H1 treatment by 9.10%, 4.19%, 4.71%, 8.95%, and 9.89%, respectively (P＜0.05). However, it is noteworthy that titratable acid content was significantly reduced by 11.21% (P＜0.05) in H2 treatment as compared to H0 treatment.Tomato yield, single fruit mass, IWUE, vitamin C, soluble sugar, soluble solids, and lycopene were increased by 29.76%, 15.23%, 29.76%, 35.65%, and 22.28%, respectively, in A1 treatment as compared to A0 treatment, 10.50%, and 41.95% (P＜0.05). By means of three evaluation methods, namely the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS), the Rank Sum Ratio (RSR) method, and Principal Component Analysis (PCA), 12 evaluation indicators were selected for a comprehensive evaluation from four aspects: yield indicators, quality indicators, economic benefit indicators, and environmental indicators (carbon emissions and carbon sequestration). The conclusion indicates that the coupling drip irrigation mode combining an irrigation level of 3,800 m³/hm², an application rate of 0.5% humic acid, and micro-nano aeration achieved the highest comprehensive evaluation score. It is recommended as the optimal water-fertilizer-gas coupling mode for high-yield, high-quality, emission reduction, and efficiency enhancement of processing tomatoes. This research can provide theoretical basis and technical support for the high-yield, high-quality, and emission reduction production of drip-irrigated processing tomatoes in the arid area of northern Xinjiang.