Abstract: Layer-by-layer assembly (LBL) is a new kind of method for preparing flame retardant natural cellulosic fiber fabric, which is based on the physical adsorption of oppositely charged polyelectrolytes and multilayer film is formed through alternate deposition on surface of fabric. Compared with traditional methods, LBL method can construct flame retardant multilayer films between the substrate and external environment, so as to inhibit the combustion process directly. In particular, adjusting the assembly conditions and process can change the mass, thickness and elementary composition of the multilayer films conveniently, so as to control the flame retardant properties effectively. Herein, the recent developments in the preparation of nanomaterials-nanomaterials, nanomaterials-polyelectrolyte, polyelectrolyte-polyelectrolyte flame retardant natural cellulosic fiber fabric via LBL method were summarized, and the related works for constructing amino-carbon nanotubes-polyphosphate and polyethyleneimine-polyphosphate intumescent flame retardant coatings on surface of ramie fabric in our lab were also introduced. Furthermore, the outlooks of future developments were discussed.