<p><i>Beauveria bassiana</i> is a widely used entomopathogenic fungus with great potential as a bioactive substance. However, there is little research on the mycelial polysaccharides from <i>B. bassiana</i>. In this study, strain <i>B. bassiana</i> C9, isolated from silkworms, was selected as a highly polysaccharide-producing strain. Two purified polysaccharides, BJ-1_P and BJ-2, were extracted from the mycelium of strain C9 and purified by graded alcohol precipitation and ion-exchange column chromatography. The weight average molecular weight (Mw) of BJ-1_P, BJ-2 were 1758.82, 18.21&#xa0;kDa, respectively, and their monosaccharide compositions mainly comprised glucose, galactose and mannose, at different molar ratios. The IC₅₀ values of DPPH, ABTS radical scavenging activities of BJ-1_P were 2.58, 8.29&#xa0;mg/mL, and BJ-2 were 2.74, 3.63&#xa0;mg/mL, respectively, indicating that both BJ-1_P and BJ-2 exhibit excellent antioxidant activities. BJ-1_P and BJ-2, at concentrations of 0.1–1&#xa0;mg/mL, significantly inhibited the production of nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in RAW264.7 macrophage induced by lipopolysaccharide and BJ-2 had excellent anti-inflammatory effect. Moreover, BJ-1_P and BJ-2 significantly inhibited melanin synthesis in B16 melanoma cell, but had no significant effect on tyrosinase activity, speculated that BJ-1_P and BJ-2 were through reducing ROS and inflammatory interleukin during the melanin synthesis process, thereby inhibiting melanin synthesis. This study presents novel findings indicating that <i>B. bassiana</i> mycelial polysaccharides can inhibit melanin synthesis. Furthermore, it was found that the polysaccharides of <i>B. bassiana</i> C9 have antioxidant and anti-inflammatory properties and possess efficacy in reducing melanin content, indicating good application prospects as functional ingredients.</p>