The present invention provides a method for preparing a negative electrode material for a battery, the method comprising the following steps: a) dry-mixing the following components, without adding any solvent, to obtain a dry mixture: polyacrylic acid, a silicon-based material, and an alkali metal hydroxide and/or an alkaline earth metal hydroxide, and an optionally present carbon material; and b) mixing the dry mixture obtained in step a) with an aqueous solvent, to obtain the negative electrode material. The present invention also provides a lithium ion battery and a solid-state battery, wherein a negative electrode of the lithium ion battery and the solid-state battery is prepared from the negative electrode material obtained by the method.