The invention discloses a variable branch modular permanent magnetic built-in outer rotor hub motor for an electric vehicle, and relates to the technical field of motors. A stator iron core is composed of Ns stator tooth modules and a stator yoke; each stator tooth module comprises a stator tooth and a winding coil wound on the stator tooth; a stator winding adopts a fractional slot concentrated winding structure to form m phases of windings; each phase is composed of k winding branches; the m phase of the windings with k winding branches are controlled by t m phases of DC-AC frequency converter; and a rotor consists of a rim and 2p rotor iron core modules. The hub motor has the advantages of high torque/power density, large reluctance torque, variable circuit control capability, capability of widening the speed regulation range, capability of realizing modular manufacturing and automatic production and the like.