The nitrogen content of nutrient solution and light intensity are two crucial factors affecting the yield and quality of controlled environment hydroponic vegetables. In this study, Purple Bok Choy (Brassica rapa var. Chinensis) was evaluated in a two-factor experiment with five levels of light intensity and five levels of nitrogen concentration. The plants were harvested on the 35th day after planting and different parameters such as shoot fresh weight, root fresh weight, anthocyanin, and soluble sugar were measured as representatives of yield and quality. This paper investigated the effects of different light/nitrogen combinations on the yield and quality of Purple Bok Choy, and established an optimal model coupled with yield and quality indicators. The result reveals that the light intensity and nitrogen concentration have a strong synergistic interaction on shoot fresh weight, root fresh weight, anthocyanin, and soluble sugar of Purple Bok Choy. A combination of light/nitrogen could be found to achieve the common improvement for the indicators with a similar change trend. This work gives valuable insights into the combinational regulation of nitrogen concentration and light intensity and provides a new idea for the comprehensive improvement of production yield and quality.