The invention discloses a preparation method for a negative pole plate of a lithium ion battery, which is used for effectively improving the areal density of the negative pole plate. The preparation method comprises the following steps of 1, preparing a high-porosity nano-porous copper electrode material by a template method, and then coating the copper electrode material on a pole plate; 2, coating paste taking graphite as a main material; 3, drying the paste, and preparing the negative pole plate of the lithium ion battery. In the preparation method, the preparation method of the nano-porous copper electrode material is simple, and reaction is completed in one time in a room temperature; and compared with nano-porous copper prepared according to technologies such as dealloying and chemical etching, the porous copper prepared by the process is simple and pure in metal constituent and large in specific area, the adhesive force of negative electrode paste of the lithium ion battery onto a copper current collector can be effectively improved, the areal density of the negative pole plate of the lithium ion battery is increased, the bonding effect of an adhesive is improved, and the capacity and the cycle performance of the battery are improved.