Gas distributor configurations were optimized for the direct synthesis of methychlorosilanes in a fluidized bed membrane reactor. The Syarrilal-O'Brien drag model was optimized to allow reasonable prediction of solid volume fraction, and the influences of opening area ratio and the number of holes of gas distributor on hydrodynamics were investigated by computational fluid dynamics simulation. The results indicated that a gas distributor with a 0.53% opening area ratio and 19 holes exhibited a steadier radial solid volume fraction distribution and lower dead zone area ratio. The effects of gas distributor configuration on the Rochow reaction were also tested experimentally, and dimethydichlorosilane selectivity and silicon conversion were both increased. This suggested that the hydrodynamic behavior using a gas distributor with Phi = 0.53% and n = 19 is beneficial for a well-distributed heat-transfer coefficient. Consequently, Phi = 0.53% and n = 19 were proposed as the best gas distributor configuration, and the reaction yield was 7.3% higher.