A powder containing Fe--Ni nano-particles and a method for manufacturing the powder, wherein the powder containing Fe--Ni nano-particles includes a carrier and Fe--Ni nano-particles. The carrier is a ceramic particle with size of about micro-meter (.mu.m). Fe and Ni atoms of the Fe--Ni nano-particles exist simultaneously on the surface of the carrier by electroless plating technology. The atomic ratio of the Fe and Ni atoms can be controlled by changing the relative concentration of the plating solution and the plating condition. The method for manufacturing the powder containing Fe--Ni nano-particles includes the following steps: preparation process, sensitization process, activation process, electroless plating process, and after-deposition process. The manufactured powder has small volume and large surface area. The contact chance between Fe/Ni bimetal and chlorinated organic substance is largely increased. It can be used to treat various environmental pollutants or for some catalytic reactions.