Black　soybean　meal　was　used　as　raw　material　to　prepare　lactic　acid　beverage　with　antioxidant　activity　through　lactic　acid　bacteria　fermentation.　Single　factor　and　response　surface　methodology　were　used　to　optimize　the　fermentation　process　of　lactic　acid　bacteria.　The　effects　of　the　solid-liquid　ratio,　inoculation　quantity,　fermentation　temperature,　and　fermentation　time　on　the　fermentation　process　were　investigated　with　DPPH　radical　scavenging　ratio　as　an　index.　The　DPPH　radical　scavenging　experiment,　OH　radical　scavenging　experiment,　ABTS　radical　scavenging　experiment,　and　lipid　peroxidation　inhibition　experiment　were　tested　to　assess　the　antioxidant　effect　of　fermented　products.　The　results　showed　that　Streptococcus　thermophilus　was　the　best　fermentation　strain,　and　the　optimum　fermentation　processes　were　solid-liquid　ratio　1:5　g/mL,　inoculation　quantity　5%,　fermentation　temperature　37.6　℃,　and　fermentation　time　36　h,　respectively.　Under　the　optimal　fermentation　conditions,　the　DPPH　radical　scavenging　ratio　was　71.56%.　The　semi-inhibitory　concentrations　of　DPPH,　OH　and　ABTS　free　radicals　in　the　fermentation　products　of　black　soybean　meal　were　2.43,　1.30　and　0.37　mg/mL,　respectively,　and　the　lipid　peroxidation　was　effectively　inhibited,　indicating　that　the　fermentation　products　had　good　antioxidant　activity　in　vitro.　The　sensory　evaluation　and　suspension　stability　of　beverage　were　90.21　and　96.8%,　respectively.　This　study　provides　a　new　idea　for　the　development　of　functional　foods　with　black　soybean　meal　as　raw　material,　and　also　provides　a　reference　for　the　further　development　of　agricultural　by-products.　©　2023,　Editorial　Department　of　Science　and　Technology　of　Food　Science.　All　rights　reserved.