Objective To study the effect of a curved hollow-fiber bioreactor on the mass transfer in an artificial liver to provide references for the optimal design of new bioreactor structures and operation parameters for clinical treatment. Methods A computational fluid dynamics (CFD) model of a hollow fiber bioreactor was established using numerical simulation. The diffusion and convection mass transfer in the hollow fiber bioreactor were considered by the K-K equation and Darcy’s law. The effects of the bending count and bending amplitude on the mass transfer behavior in a hollow fiber bioreactor were analyzed. Results Dean vortices were generated in the curved hollow fiber bioreactor owing to the centrifugal force. This promoted solute remixing in the tube and thereby, diffusion mass transfer. Meanwhile, the higher transmembrane pressure in the curved hollow fiber bioreactor also promoted convection mass transfer. Consequently, the Dean vortices and high transmembrane pressure increased the solute clearance rate. When the bending counts were 0, 3, 6, 9, and 12 and the bending amplitude was 1 mm, the bilirubin clearance rates were 113.44, 117.95, 121.89, 129.89, and 140.57 mL/min respectively. When the bending amplitudes were 0, 0.5, 1, 1.5, and 2 mm and the bending count was three, the bilirubin clearance rates were 113.44, 115.45, 117.95, 120.16, and 123.14 mL/min, respectively. Conclusions The curved hollow fiber bioreactor improved the toxin removal efficiency in the artificial liver.