A ceramic membrane with multichannels generally has a higher specific area and larger throughput compared to that with a single channel, which is beneficial to the industrialization of ceramic membrane contactors for SO2 absorption. In this work, the mass transfer performance of SO2 absorption into NaOH solution was investigated at various gas and liquid operating conditions in a membrane contactor packed with a 19-channel hydrophilic membrane. The results showed that increasing the NaOH concentration can offset the effect of membrane thickness. To analyze the mass transfer process, a 3D mass transfer model was developed to simulate the concentration distribution of the components. The simulated SO2 fluxes were consistent with the experimental results. Additionally, the mass transfer model was applied to optimize the structure of channels in multichannel ceramic membranes. The operational mode of the multichannel ceramic membrane is optimized by blocking some inside channels to reduce the mass transfer resistance.