The embodiment of the invention discloses a silicon monoxide composite material, a preparation method thereof and a lithium ion battery, and the preparation method comprises the following steps: introducing a protective gas into a vapor deposition furnace, and preheating a silicon monoxide raw material at the same time, so that part of the silicon monoxide raw material is subjected to a disproportionation reaction; and continuously introducing protective gas and carbon source gas, and carrying out chemical vapor deposition on the preheated silicon monoxide raw material so as to form the carbon nanotubes on the surface of the silicon monoxide. According to the embodiment of the invention, the carbon nanotube can be catalytically grown on the surface of the silicon monoxide through the in-situ self-generated catalyst, the conductivity and the first coulombic efficiency of the silicon monoxide are improved, and the preparation process is simple.