This paper describes three-dimensional computational fluid dynamics (CFD) simulations of gas-liquid flow in a novel laboratory-scale bioreactor contained dual ventilation-pipe and double sieve-plate bioreactor (DVDSB) used for sophorolipid (SL) production. To evaluate the role of hydrodynamics in reactor design, the comparisons between conventional fed-batch fermenter and DVDSB on the hydrodynamic behavior are predicted by the CFD methods. Important hydrodynamic parameters of the gas-liquid two-phase system such as the liquid phase velocity field, turbulent kinetic energy and volume-averaged overall and time-averaged local gas holdups were simulated and analyzed in detail. The numerical results were also validated by experimental measurements of overall gas holdups. The yield of sophorolipids was significantly improved to 484 g.L-1 with a 320 h fermentation period in the new reactor. (C) 2016 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.