Negative electrode paste of a lithium ion battery is formed by stirring a negative electrode material and a solvent, the negative electrode material comprises a negative electrode active substance, a conductive agent, a thickening agent and a binding agent and also comprises a polyether modified organic silicon polymer, the polyether modified organic silicon polymer accounts for 0.2-0.5% of the total weight of the negative electrode material, and the mass ratio of the polyether modified organic silicon polymer to the thickening agent is 1:(1.5-3). An organic silicon polymer is introduced into a negative electrode paste formula system so as to improve paste stability; the addition quantity of the water-soluble thickening agent is reduced, so that the energy density of the lithium ion battery is improved; and meanwhile, due to the flexibility of a Si-C structure in the organic silicon polymer, the compaction density of a pole plate is improved, the negative electrode paste is good in high-temperature resistant performance, the high-temperature cycle property and the high-temperature storage performance of various materials can be improved, and the problems of ingredient preparation difficulty, coating abnormality and the like caused by poor matching of main materials such as the water-soluble thickening agent and the water-based binding agent or the water-soluble thickening agent and graphite can also be remarkably solved.