Rhizopus oryzae produces important organic acids such as lactic acid, and has important application value in many fields. In this study, a fungus was isolated from Baijiu Daqu of Beidacang, Heilongjiang Province, and the strain was identified and named as Rhizopus oryzae WSW-LYN-001 using internal transcribed spacer(ITS) identification. The results showed that using glucose as the carbon source, after 48 hours, the pH of fermentation broth reached around 3.2. After 84 hours of fermentation, the lactate production maintained at around 70 g/L. The passage number could affect the morphology of fungal hyphae(flocculent and globular mycelium clusters appeared), which in turn affected lactate production. After 60 hours of fermentation, the lactate production in the fermentation broth of spherical mycelium was higher than that of flocculent mycelium. After pH optimization, the spherical mycelium produced the maximum lactic acid yield of 134.25 g/L after 60 hours of fermentation at an initial pH of 7.