<p>Traditional radial coaxial magnetic gears (RCMG) limit their application in high-power density scenarios due to low torque density, local magnetic leakage, and insufficient magnetic field modulation. To solve this problem, a dual-modulated RCMG with Z-type modulated stator and asymmetric Halbach array is proposed, and the high-speed/low-speed rotor adopts asymmetric Halbach permanent magnets, which significantly improve the air-gap magnetic flux density and reduce non-operating harmonics to improve the torque density. Combined with the Z-type modulated stator topology, the magnetic field of the permanent magnet is dual-modulated in both axial and transverse directions. The research analyzes the magnetic field characteristics by establishing a finite element model, and verifies its working principle and magnetic coupling characteristics. Based on the transmission system model, a dynamic model with two subsystems is constructed, and the free vibration characteristics are analyzed and the system exhibits the characteristics of “dual type sixth” mode, which is related to the stiffness distribution of the structure. On the basis of free vibration analysis, the forced vibration equation is established, and the time/frequency domain response is solved by regular transform and transfer function method, and it is found that when the excitation frequency is close to the natural frequency, the forced vibration is still simple harmonic, and only the corresponding degrees of freedom resonance displacement increases significantly, and the amplitude of the remaining degrees of freedom is small. In summary, the proposed RCMG improves the transmission performance through structural innovation, and the modal characteristics and dynamic laws revealed provide key theoretical and technical support for the design optimization, resonance suppression, and engineering application of high-power density magnetic gears.</p>