This study aims to investigate the microbial fermentation technology and bioactivity of melanin. In this study, Aureobasidium melanogenum GLA-1 was used as the melanin-producing strain. The fermentation process for the production of melanin was optimized using single factor and orthogonal experiments. Melanin was purified by alkali-soluble alcohol precipitation and characterized by solubility test and UV-vis spectrum, and then the antioxidant, antiultraviolet radiation and antibacterial activities of melanin were also studied. The titer of melanin was 1.639±0.115 g/L under the optimal medium and fermentation conditions, which was 4 times higher than that before optimization. The melanin purified from the fermentation broth was preliminarily identified as eumelanin. When the concentration of melanin was 100 mg/L, the scavenging rate on ABTS⁺, DPPH, hydroxyl and superoxide free radicals were 99.32%±0.07%, 89.71%±0.47%, 45.95%±1.36% and 50.85%±4.01%, respectively. The melanin has a very significant antiultraviolet radiation activity. Besides, the melanin had good inhibitory activity against Escherichia coli, and the optimal inhibitory concentration was 0.4 mg/mL. However, there was no inhibitory activity against Staphylococcus aureus in the concentration range examined. The above results provided some basic research data for the fermentation production and application of melanin from A. melanogenum.