The invention discloses a fibrous nanosilicon preparation method. The method is characterized in that the method comprises the following steps: taking
magnesium powder and silica-based
chrysotile according to a
magnesium: silica
mole ratio of 0.3-3:1, and uniformly mixing to obtain a mixture; filling the mixture to a reaction apparatus, evacuating, continuously introducing
argon to the reaction apparatus, heating to 500-800DEG C, carrying out a heat insulation reaction for 0.3-6h, cooling to
room temperature, stopping the introduction of
argon, and collecting a product obtained a
combustion reaction; and mixing and reacting with dilute
hydrochloric acid, filtering or centrifuging a material after the above reaction, washing the obtained
solid precipitate with deionized water,
drying, and milling to prepare fibrous nanosilicon. The preparation method has the advantages of easily available raw materials, simple apparatus and technology, and
environmental protection, and the prepared fibrous nanosilicon has the advantages of excellent strength, excellent
creep resistance and excellent high
temperature resistance, and has good application prospects in the
nanowire field, the switch field, the line field, the high-performance
optical fiber field, the
energy storage field, the environment
treatment field, and the medical and health field.