The invention discloses a lithium fluoride-nickel monoxide nanocomposite and a preparation method thereof. The composite includes lithium fluoride and nickel monoxide in a mole ratio of 1:1-1:4. The preparation method includes: grinding lithium fluoride and nickel monoxide and then performing mixing in proportion, and conducting tabletting to obtain a target for pulsed laser deposition, subjectingpulse laser generated by a laser to lens focusing, then bringing the focused pulse laser incident to the target, and performing deposition in an argon atmosphere so as to obtain a lithium fluoride-nickel monoxide nanocomposite film. An electrode prepared from the film has good charging-discharging cycle reversibility, an initial specific capacity of 170-250mAh/g, a reversible specific capacity of200mAh/g, and still has a capacity of 180mAh/g after 50 cycles. The material provided by the invention has the characteristics of good chemical stability, high specific capacity and simple preparation method, and is suitable for lithium ion batteries.