Abstract: To address recurring quality issues in high/low voltage distribution cabinet installation—including excessive verticality deviations, insufficient busbar connection torque, and chaotic secondary wiring—this study proposes a three-stage precision quality control system comprising "foundation preparation, fine-tuning, and final sealing." During the foundation phase, a level instrument is used to repeatedly measure channel steel elevation and straightness (maximum deviation ≤1.8mm), with initial cabinet positioning deviation controlled within ±5mm after gasket fine-tuning. The fine-tuning phase employs magnetic line-of-sight plumb line detection for verticality measurement (actual deviation 1.0–1.4mm/m), torque wrenches for initial/final bolt tightening (M12 torque 68N·m), and ensures cabinet gaps ≤1.5mm with panel surface flatness ≤2.1mm. The final sealing phase involves busbar wrapping with heat-shrink sleeves, insulator cleaning with alcohol, and interphase/ground insulation resistance maintained at 540–590MΩ. Case study application from the Sci-Tech Innovation Center"s 10kV power distribution project (12 high-voltage cabinets and 26 low-voltage cabinets) demonstrates that all performance metrics exceed industry standards, effectively resolving installation defects and significantly enhancing electrical reliability.