The invention relates to a spherical lithium ion battery positive electrode material with a nano-scale two-phase gradient distribution structure and a synthetic method therefor, belongs to the technical fields of a lithium ion battery material and a manufacturing process thereof, and aims to solve the problems of short cycle life, low structural stability and thermal stability and severe material surface secondary reaction of the convention positive electrode material of the lithium ion battery. The spherical lithium ion battery positive electrode material with the nano-scale two-phase gradient distribution structure comprises two phases, wherein one phase is a Li<2>MnO<3> phase in gradient distribution, and the other phase is a uniformly or non-uniformly distributed layered LiMO<2> phase. The synthetic method for the lithium ion battery positive electrode material comprises the following steps of 1, preparing a solution; 2, preparing a precursor; and 3, performing high-temperature solid-phase synthesis. The positive electrode material provided by the invention is applied to the lithium ion battery.