The invention discloses a manganese positive pole of a modified lithium ion battery, and a preparation method of the manganese positive pole; the positive pole is formed by sequentially covering a positive pole material layer and a conductive thin film layer on a current collector; the preparation method comprises the following steps of: mixing manganese material, a conductive agent and a high polymer bonding agent, and then coating the mixture onto one surface of the current collector; and drying, and generating a layer of conductive thin film on the surface of the current collector to obtain the manganese positive pole of the modified lithium ion battery. The positive pole is good in conductivity and stable in high-temperature cycle performance; and the preparation method is simple and rapid, and can be used for industrial production.