A carbon sphere/polyacrylonitrile fiber material and a preparing method and applications thereof are provided. The material includes one or more polyacrylonitrile threads covered with carbon spheres the particle size of which is 50 nm to 5 [mu]m. The polyacrylonitrile threads have a fusiform structure adopting the carbon spheres as nodes. The preparing method is simple, and the material is low incost, safe and environmentally friendly, and has huge application value in the field of oil-water emulsion separation.