Compared with monolayer molybdenum disulfide (MoS₂), bilayer MoS₂ can exhibit higher carrier mobility and smaller band gap due to its unique interlayer interaction, and has better electron transport characteristics. It is considered to be an ideal channel material for the next generation of electronic devices. The precise regulation of the physical, chemical and electrical properties of bilayer MoS₂ by doping is a key technical path to promote its practical application. However, the influence mechanism of doping on defect structure and interlayer interaction still needs to be further explored. In this paper, vanadium (V) doped bilayer MoS₂ thin films were prepared by three-source shunt chemical vapor deposition. The effects of V doping on the defect structure, interlayer interaction and electrical properties of the bilayer films were systematically studied. It is found that V doping can significantly reduce the formation energy of S vacancies, and can form V_Mo substitution defects and S vacancy complex defect structures. This results in the fact that when the doping concentration of vanadium is less than 10%, the bilayer MoS₂ film can still maintain the n-type conductive characteristics. Although V doping does not change the carrier transport type of the bilayer MoS₂ material, it significantly increases the electron binding energy and the interlayer Mo-S bond, and increases the interlayer binding energy under AA and AB stacking by 2.71 % and 2.44 %, respectively. The enhancement of interlayer coupling not only weakens the scattering of carriers, but also prolongs the relaxation time of carriers. Consequently, under high gate voltage conditions, the drain current of the doped device is higher than that of the undoped device. Finally, the V-doped device maintains a high switching ratio (~10⁷), and its high-field conductivity is also significantly improved. This study not only successfully developed the controllable doping process of bilayer MoS₂, but also opened up a new technical path for the precise regulation of the interaction between the layers of two-dimensional materials, which has important theoretical guiding significance and practical application value for promoting the industrial application of two-dimensional MoS₂-based electronic devices.