Y₂MgTiO₆(YMT)-based ceramics have become core candidates for high-frequency electronic devices such as millimeter-wave communications due to their high dielectric constant (ε_r), ultra-high quality factor (Q×f) and low dielectric loss. However, most of the existing studies focus on the ion doping effect at a single scale (such as lattice parameters or macroscopic properties), and the structure-activity relationship between atomic bonding, lattice distortion, phonon behavior and dielectric properties has not yet been fully revealed, especially the regulation law of the coupling mechanism of chemical bonding and lattice vibration on doped ions is still theoretically blank. This limits the design and performance control of high-performance microwave dielectric ceramic materials.