<p>This study proposes a novel deep cryogenic-electroshock composite treatment (DCT-EST) to enhance the strength-ductility synergy of TC11 titanium alloys. Through a comparative analysis of uniaxial tensile tests, it is found that, compared to the original specimen (ORI), the mechanical properties of the treated specimen are significantly improved after the DCT-EST: while the average tensile strength remains unchanged (with a change rate of less than 1%), the average engineering strain at fracture and the strength-ductility product have significantly increased by 20.1% and 20.7%, respectively. Multiscale microstructural characterization was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), electron back-scattered diffraction (EBSD), and transmission electron microscopy (TEM). The results indicate that ‌DCT‌ promotes ‌short-range diffusion of Mo atoms‌, thereby facilitating the partial phase transformation of β phase → metastable β phase → α_s phase. This leads to grain refinement from 2.24 μm to 2.03 μm and an increase in dislocation density from 5.97 × 10¹⁴ m⁻² to 7.14 × 10¹⁴ m⁻², resulting in a synergistic improvement in both strength and ductility of the material. Subsequent EST reduces the dislocation density to 6.88 × 10¹⁴ m⁻² and homogenizes stress distribution, further enhancing the ductility of TC11 titanium alloys. Finally, molecular dynamics simulation revealed the evolution of dislocations (1/3 &lt; 1–100 &gt;) in TC11 titanium alloy under DCT-EST conditions and the directional migration process of Mo atoms in the β phase. Combined with theoretical analysis and a multi-field microstructural evolution model, the cooperative regulation mechanism of the DCT-EST process on the multiphase and multiscale strength-ductility synergy of titanium alloys was elaborated in detail.</p>