As a family of important inorganic layered materials, layered double hydroxides (LDHs) have attracted considerable attentions owing to their potential applications in wide areas. Generally, the size, shape, uniformity and dispersity of LDHs have great effects on their application properties. Herein, we report an efficient approach to prepare surfactant-free transparent dispersions of monodispersed CO32- intercalated MgAl-LDH nanoparticles using a high-gravity-assisted intensified co-precipitation method in a rotating packed bed (RPB) reactor, followed by hydrothermal treatment. After a rapid co-precipitation in the RPB reactor, monodispersed MgAl-LDH nanoparticles with an average particle size of about 31 nm can be obtained. As compared to that in a stirred tank reactor (STR), the product from the RPB has much smaller particle size, narrower size distribution and higher optical transparency. More importantly, the reaction time can be significantly reduced from 20 min to 20 s, realizing an efficient contin...