Negative active material and preparation method thereof, secondary battery, battery module, battery pack and power utilization device

The invention discloses a negative electrode active material and a preparation method thereof, a secondary battery and an electric device. Wherein the negative electrode active material (6) comprises: a core material (61) comprising a silicon-based material; a first coating layer (62) on at least part of the surface of the core material (61), the first coating layer (62) comprising SiOx, 1 < x < 2; and a second coating layer (63) on at least part of the surface of the first coating layer (62), the second coating layer (63) comprising a fluorinated carbon material.