Limited information is available on the impact of Enhanced Efficiency Nitrogen Fertilizers (EENFs) on soil methane (CH4) uptake and its relationship with diffusion in dryland farming. To address this, we conducted a two-year cotton (Gossypium hirsutum L.) field experiment under drip irrigation in arid northwestern China. The study assessed the effects of two EENFs (ESN and SuperU) and conventional urea, applied at 120 and 240 kg N ha-1, on surface CH4 uptake and profile diffusion. ESN is polymer-coated urea, and SuperU is a stabilized N fertilizer containing urease and nitrification inhibitors. ESN and SuperU were fully side-banded at pre-plant due to their low solubility and tendency to float, while urea, with its higher solubility, was applied via fertigation. We measured surface CH4 uptake using static chambers and CH4 concentrations at 5, 15, 30, and 60 cm soil depths using in-situ diffusive sampling. CH4 diffusion rates were calculated using the concentration gradient method. Soil ammonium, (NH4+) and nitrate (NO3-) nitrogen concentrations, moisture, and temperature were determined. The results showed that, compared to urea, applying ESN and SuperU reduced cumulative surface CH4 uptake (30.1 %-42.7 %) and increased soil NH4+ (30.1 %-33.5 %) and NO3- (20.6 %-46.0 %) concentration. Soil CH4 concentration decreased with depth, with the highest CH4 oxidation in the 15-30 cm layer. CH4 concentrations in the 5-50 cm layer and diffusion rates in the 0-60 cm layer were positively and negatively correlated with soil moisture, respectively, but weakly influenced by N fertilizer treatment. Dry-wet alternation and low soil moisture limited the response of CH4 concentration and diffusion to changes in mineral N. Additionally, weak correlations were found between surface CH4 uptake rates and profile diffusion rates across all treatments. The reduced surface CH4 uptake with ESN and SuperU was mainly due to increased NO3- concentrations. This study highlights the risk of reduced CH4 uptake with ESN and SuperU and improves understanding of CH4 concentration and diffusion in drip-mulch irrigation systems.