Janus nanosheets of polymer inorganic layered composites are fabricated by crushing the corresponding Janus composite hollow spheres, which are synthesized by materialization of an amphiphilic emulsion interface with self-organized sol-gel process and subsequent polymer grafting onto the lipophilic side. The Janus composite nanosheets serve as solid surfactants to stabilize emulsion droplets, which are tolerant against solvents. Janus balance of the composite nanosheets is tunable crossing from more lipophilic to hydrophilic by alteration of polymer content. Thereafter, continuous phase of the emulsions can be inverted.