The present disclosure provides a lithium-rich electrode plate of a lithium-ion battery and a preparation method thereof. The preparation method of the lithium-rich electrode plate of the lithium-ion battery comprises steps of: (1) in a protective gas environment, melting a lithium ingot to obtain a melting lithium; (2) in a vacuum environment, heating and drying ceramic particles to obtain dried and anhydrous ceramic particles; (3) in a protective gas environment, adding the dried and anhydrous ceramic particles into the melting lithium, stirring to make them uniformly mixed to obtain a modified melting lithium; (4) in a protective gas environment, uniformly coating the modified melting lithium on a surface of an electrode plate to be lithium rich to form a lithium-rich layer, which is followed by cooling to room temperature to obtain a lithium-rich electrode plate of a lithium-ion battery. The lithium-rich electrode plate is prepared according to the preparation method.