<p>The development of cave tourism highly depends on the landscape lighting. However, the impact of lighting on the growth of plants and animals within the caves can further alter the geological conditions and the growth characteristics of organisms, severely threatening the ecological balance of karst caves. This study presents a comprehensive investigation into the impact of landscape lighting on the ecosystem of karst caves in Southwest China. Field research was conducted over 6 years, from 2017 to 2023. It comprehensively collected data on the color, intensity, and mode of landscape lighting, tourists’ satisfaction with the lighting, the types of plants under the lighting, and the associated animals. The research results show that: (1) Tourists were satisfied with the lighting color but found the brightness inadequate. (2) Different light spectra led to diverse phototrophic plants, which showed a seasonal growth cycle under prolonged illumination. (3) In the sixth year of the observation, a large number of animals were found to breed around the phototrophic plants. (4) Based on tourist satisfaction scores and phototrophic organism characteristics, a scientific and aesthetic cave lighting design reference was proposed. This study suggests using lighting technology to control phototrophic organism growth, preventing cave ecosystem damage from improper lighting and offering practical guidance for sustainable karst cave use.</p>