Unsupported powders include silver, gold, palladium, platinum and other precious metal elemental nano powders. Due to the strong surface effect of nanoparticles, the nanoparticles are easily agglomerated with each other. Usually in the preparation process or after powder products are obtained, some protective agents with well dispersive will be used to cover the surface of the particles. At present, the non-loaded noble metal nanoparticles which have been industrialized and applied in industry mainly include silver nanoparticles, gold nanoparticles, platinum nanoparticles and palladium nanoparticles.In addition, the paste made of precious metal colloid has higher performance-price ratio and stable product quality, which can be used to develop new generation of high-performance electronic products. At the same time, the precious metal colloid itself can also be directly used in electronic circuit manufacturing and Power encapsulation.