The invention discloses a chili hydroponic method which includes the following steps that 1, chili seeds are cleaned, sterilized and wrapped with wet gauze till white buds are exposed; 2, roots are downwards placed into small holes formed in a sponge block, and then the sponge block is placed into a seedling nutrient solution for seedling culture; 3, the sponge block after seedling culture is transferred into a circular hydroponic nutrient solution for culture. According to the chili hydroponic method, growth throughout the whole year can be achieved under the red light ranging from 650 nm to 670 nm, the blue light ranging from 440 nm to 460 nm and the compound light, meanwhile three-dimensional culture can be conducted, the yield in unit area is high, no plant disease and insect pest exist, and growth of plants can be adjusted under an artificial light source.