To obtain high-quality iris images, a phone iris-recognition lens is designed using the optical design software ZEMAX in this study. The phone lens comprises four plastic aspheric lenses. The total working distance, total length, and F number of the phone lens are 200--330 mm, 4.09 mm, and 2.4, respectively. In the design results, the modulation transfer function at 275 mm exceeds 0.4 at one-half the Nyquist frequency of the lens. The distortion is lower than 0.6%, and the relative illumination exceeds 83%. Image evaluation and tolerance analysis confirm that the system has small distortion, a large variable working distance, excellent image quality, and stable performance, thus meeting the processing requirements of iris recognition lenses.