Bioinspired by the spinning of spider silks,the biomimetic preparation of elastomeric fibers with micro/nano structures on the surfaces was attempted,and as a result,three types of ultrafine fullvulcanized powdered nitrile-butadiene rubber(UFPNBR)/thermoplastic polyurethane(TPU) fibers were made.The first fiber was only decorated by the micron-sized grooves on the surface,and the second fiber was dotted by both the micron-sized grooves and nanometer-sized spheres on the surface,while the third fiber was helical and with a concave-convex surface.The biomimetic preparation mainly consisted of four steps,and the formation mechanism was described as an integrated mechanism of diffusion,coagulation,self assembly,and microphase separation.The micro/nano structures on the fibers were controlled by changing the mass ratio of UFPNBR to TPU and environment of vertical stretching.The UFPNBR/TPU elastomeric fibers were hoped to have an integrated function of superhydrophobicity,self cleaning,and mechanical improvement of toughness or strength. Bioinspired by the spinning of spider silks, the biomimetic preparation of elastomeric fibers with micro / nano structures on the surfaces was attempted, and as a result, three types of ultrafine fullvulcanized powdered nitrile-butadiene rubber (UFPNBR) / thermoplastic polyurethane (TPU) fibers were made. The first fiber was only decorated by the micron-sized grooves on the surface, and the second fiber was dotted by both the micron-sized grooves and the nanometer-sized spheres on the surface, while the third fiber was helical and with a concave-convex surface. The biomimetic preparation mainly consisted of four steps, and the formation mechanism was described as an integrated mechanism of diffusion, coagulation, self assembly, and microphase separation. The micro / nano structures on the fibers were controlled by changing the mass ratio of UFPNBR to TPU and environment of vertical stretching. The UFPNBR / TPU elastomeric fibers were hoped to have an integrated function of superhydrophobicity, self cleaning, and m echanical improvement of toughness or strength.