A novel approach to synthesize nanostructure composites of layered double hydroxide ammonium polyphosphate (LDH-APP) is reported. hollow LDH-APP nanoshells were synthesized by simply mixing precursor solutions and systematically characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and Brunauer-Emmett-Teller (BET) techniques. The as-fabricated LDH-APP-PP (polypropylene) composites using hollow LDH-APP nanoshells as nanofiller show excellent flame-retardant performance, which is much better than that of LDH-PP. It is expected that such a kind of LDH-APP composite materials may have potential applications in the field of industrial flame-retardant.