Abstract: To enhance the combustion performance and reduce pollutant emissions of heavy-duty gas turbines, the impact of fuel hole arrangement patterns on the combustion and emission characteristics of natural gas swirl nozzles was investigated. Based on the blade shape, four hole arrangement schemes were designed in total, with two schemes featuring centralized arrangement at the center of the blades and the other two adopting a relatively dispersed arrangement. A comparison was made among the four schemes regarding corresponding cold state fuel mixing performance and combustion thermal state performance under 100% load condition. Cold state calculation results indicate that when the fuel holes are concentrated in the middle of blades, the mixing effect with air is poor, with the fuel mainly concentrated in the root area of the swirler blades and unable to disperse circumferentially. The average non-uniformity of the equivalence ratio at the nozzle outlet can reach 15.19%. In contrast, for the dispersed arrangement schemes, the fuel mixing performance is good, and the average non-uniformity of the equivalence ratio at the nozzle outlet is only 1.49%. Thermal state calculation results show that when the arrangement of fuel holes is concentrated, localized high-temperature regions are generated during combustion, leading to an increase in local NO_x emission. However, in dispersed arrangement schemes, the combustion temperature is no more than 1 800 K, and the NO_x emissions remain at a low level. A comprehensive analysis concludes that the fuel holes should be arranged as dispersedly as possible, with the outer holes positioned close to the outer edges of the swirl blades and the inner holes appropriately distanced from the blade roots.