A preparation method of a lithium-ion battery electrode sheet includes: adding a powdered thermal decomposition additive, an active material, a binder, and a conductive agent into a solvent according to a predetermined ratio and a specific order, performing continuous stirring until the solvent is uniformly mixed, obtaining an electrode slurry, coating the prepared and obtained electrode slurry onto a current collector to obtain a lithium-ion battery wet electrode sheet, and heating and drying the lithium-ion battery wet electrode sheet. The lithium-ion battery electrode sheet with the vertical vent structures is accordingly prepared and obtained. The product includes a current collector, an electrode coating layer, and a plurality of vertical vent structures which are uniformly distributed.