The fermentation technology of dandelion black tea was optimized by Box-Behnken response surface method. Combined with sensory evaluation and biochemical analysis, the effects of fermentation conditions such as temperature, time and humidity on the functional components, sensory quality and antioxidant function of dandelion black tea were evaluated. Results showed that under the conditions of fermentation temperature of 25°C, humidity of 80% and time of 15 h, functional properties of dandelion black tea were the highest, of which, chlorogenic acid was 1.53 mg/g, water extracts of tea were 32.59%, tea polyphenol was 1.535%, DPPH radical scavenging rate was 95.9%, and tea soup had good sensory quality, orange and mellow taste. Various volatile flavor components among different fermentation treatments with the maximum difference of 45.3% were found, including 17 alcohols, 14 aldehydes, 12 ketones, 6 esters, 6 organic acids, 5 sulfur compounds, indicating that optimized fermentation process could change the types and quantity of volatile compounds, thus affecting sensory quality of dandelion black tea. This study could provide a reference for the development of high-quality functional dandelion black tea.