In order to take both of the lowspeed and hightorque characteristics of permanent magnet machines and the operating range of constant power range into account, a fluxcontrollable permanent magnet vernier (RVFCPMV) machine was proposed. Taking a threephase RVFCPMV machine with 22/2pole as an example, the RVFCPMV machine topology was introduced firstly. The equivalent magnetic circuit method was used to reveal the characteristics of lowspeed and hightorque. Different with the traditional flux weakening method by injecting daxis demagnetization current component into armature windings, a new flux weakening control method was proposed, of which the key was to change the magnetic circuit reluctance based on the nonlinear performance of ferromagnetic materials by adjusting the excitation current. The electromagnetic performances of RVFCPMV machine were calculated and analyzed using finite element analysis, which verified the characteristics of lowspeed and hightorque output and the capacity of flux weakening control.