By taking advantages of the ultrasonic effects of dispersion, crushing, activation and initiation, the nano-aluminium/polystyrene (nano-Al/PS) encapsulation particles were prepared. The nano-Al particles were surface pretreated with the surfactants under ultrasonic irradiation. Then, the dispersion polymerization of styrene was initiated on the surface of nano-Al particles through ultrasonic irradiation in ethanol medium. In this reaction, the stabilizer was poly(N-vinyl pyrrolidone) (PVP), and the initiator was 2,2-azobisizobutyronitrile (AIBN). Finally, the encapsulation particles were respectively characterized by SEM, TEM, FTIR, thermogravimetric analysis (TGA), X-ray diffraction patterns (XRD) and X-ray photoelectron spectroscopy (XPS). The results showed that the size of nano-Al/PS encapsulation particles were about 2.0m. The polystyrene encapsulated nano-Al particles structure had good sphericity and smooth intact surface. Key words: nano-aluminium/polystyrene; encapsulation particles；dispersion polymerization；ultrasonic irradiation