The invention discloses a method with single-channel mixing adapter and precipitation for manufacturing nano-powder. The single-channel mixing adapter includes mixing adapters and stabilizers with mixing mechanisms inside, which connect with each other in succession. A gas distributor is installed on the pipeline connecting with liquid at the liquid entry end of the mixing adapter. The liquid, firstly, passes through the mixing adapter, in which the liquid, after being mixed uniformly, becomes sediments. Then, the sediments enter into the stabilizer to grow stably, after which products flows out through a material guiding pipe. Then, the products, after being matured, separated, dried or drily roasted, become nano-powders. By adopting the method with single-channel mixing adapter and precipitation to produce nano-powder, the liquid can be mixed uniformly in the mixing adapter. At the same time, the produced sediments can grow stably in the stabilizer. Also, by adopting the method withsingle-channel mixing adapter and precipitation to produce nana-powder, the nucleation process and the growing process of the sediments in precipitation reaction can be separated. The diameter of theproduced particles can be adjusted. The dispersity of the particles is good. The distribution of the particles is narrow. The differences of the features of the particles are small. The method with single-channel mixing adapter and precipitation for manufacturing nano-powder is simple and is convenient for industrial manufacturing.