An experiment on the effect of carbon source, nitrogen source, metal ion and salinity on degradation of aniline blue dye by Mucoromycotina sp. HS-3 was carried out under statically air-opened condition. The results showed that the optimum medium for single factor were 1 g/L glucose, 0.6 g/L ammonium sulfate, 0.15 mmol/L Fe3+, and less than 50 g/L salinity, respectively. Under each optimum condition above, the decolorization rate of aniline blue dye (100 mg/L initial concentration) was over 95% after 5 days. In addition, a toxicity test was carried out using a bioassay based on growth inhibition of Vigna unguiculata (a plant species) and Bacillus subtilis (a bacterial species) by aniline blue solution before and after degradation. The result showed that the toxicity of aniline blue after degradation had reduced obviously. So this strain had a good application potential for treating dyeing wastewater mainly consisted of aniline blue.