In order to improve the recognition rate of finger vein, the quality of the finger vein image needs to be improved first. The key factor affecting the image quality is the finger vein collection equipment, and the near-infrared LED light source system of the collection device directly determines the quality of the finger vein imaging. However, the shape and internal structure of the human fingers are different, and the structural parameters are different. If the design of the device’s near-infrared light source is unreasonable and if the structural parameters of the light source array are incorrect, it is impossible to collect the details and features inside the finger vein, which results in a decrease in the recognition rate of the finger vein. This paper proposes a light source design method for equilateral triangle arrangement of near-infrared LED arrays to optimize the structural parameters of the triangle array. The experimental results show that the improving of the quality of the collected finger vein images can help improve the recognition rate of the finger vein images identifying.