Abstract: Iris recognition technology is one of the most secure biometric identification methods. However, due to the small size of the iris, its tendency to be occluded, and its physiological characteristic of frequent movement, data acquisition remains the greatest bottleneck restricting the development of iris recognition. In particular, during long-distance recognition under complex environments, iris images are difficult to acquire, with limited system capacity and a high risk of defocus, resulting in low recognition success rates. To address these challenges, this paper combines light field imaging with iris recognition and proposes a large depth of field and long-distance iris acquisition method based on light field imaging. Comparative experiments with conventional long-distance infrared imaging devices at the same distances were conducted. The proposed method enables real-time iris acquisition within a range of 0.4 m to 1.5 m, covering close, medium, and long distances. Furthermore, by leveraging the digital refocusing capability of light field imaging, the depth of iris acquisition is greatly enhanced: for close-range imaging (0.4 m), the acquisition capacity increased from 1 cm to 17 cm; for medium-range imaging (0.7 m), from 18 cm to 37 cm; and for long-range imaging (1.5 m / 1 m), from 10 cm to 16 cm. This work introduces innovation at the source of iris image acquisition, and through the expanded depth of field and digital refocusing enabled by light field imaging, effectively addresses the limitations of traditional systems, such as small acquisition capacity, difficulties in accurate focusing, the need for high user cooperation, resulting in low recognition success rates. The proposed approach provides a new perspective and method for long-distance, passive iris acquisition.