Aiming at the problems of high energy consumption, complex wiring, high layout cost, limited use environment, and limited function of conventional plant lighting equipment such as fluorescent lamps, sodium lamps, etc., this paper develops a type of laser device for plant growth with nanometer lasers based on the design of an intelligent control system of an immune algorithm, constant current driving circuit of the laser, pulse power supply, and rotatable intelligent platform to make the device more stable, reliable, practical, and energy efficient, and provides a useful reference for the innovation and application of materials, processes, and methods of plant lighting. The effects of nanometer laser light supplementation on the growth of purple lettuce, romaine lettuce, Chinese cabbage, and you-mai vegetable have been studied with the vegetables mentioned above as experimental materials and with natural light as the control sample. The results show that the nanometer laser device significantly increases stem height, stem thickness, leaf area, leaf number, and chlorophyll content, effectively promotes plant growth, and achieves efficient cultivation. In the future, studies of the effects of laser treatment on plant physiology and biochemistry will be sped up to explore the molecular biological mechanism of lasers to promote application and technological innovation of lasers in lighting for plant growth and the laser device in productivity.