The invention discloses a preparation method for a negative plate of a lithium ion battery. The preparation method comprises the following steps of coating the particle surface of an alloy material with a layer of coating material; uniformly mixing the alloy material coated with the coating material, a carbon material, a conductive agent, a binding agent and a first solvent which is not dissolved in the coating material according to a certain proportion to form a negative electrode paste; uniformly coating the negative electrode pate on a negative current collector, drying and compacting the negative current collector to the negative plate to be processed; washing the negative plate to be processed with a second solvent which is easy to dissolve in the coating material, and drying the alloy material to form the negative plate after dissolving the coating material coated on the surface of the alloy material. Further, the invention also discloses the negative plate of the lithium ion battery, obtained according to the preparation method, and the lithium ion battery.