Abstract: Aiming at the challenge of dilution control in deep-hole mining of a narrow gold vein, statistical analysis was applied to examine the distribution characteristics and main controlling factors of ore dilution rates in stopes within the target mining area. A quantitative stability characterization model for stopes was built based on coupled analysis of rock mass quality classification and the Mathews stability graph method, revealing the correlation between the dilution rate and stope structural parameters. Under the dual constraints of stope safety and low ore dilution, a differentiated hierarchical borehole layout scheme was proposed. The charging structure was improved by changing from continuous charging to a dual-interval coupled charging method. Furthermore, the row spacing in deep-hole blasting was increased from 0.7 m to 1.0 m. Industrial tests in trial stopes verify that the unplanned ore dilution rate of the optimized stopes is significantly reduced to 9.3 %, representing a 65.5 % reduction compared to the original method. Through the synergistic optimization of structural parameter adjustment and blasting process control, this study achieves safe, efficient, and low-dilution mining in narrow-vein deep-hole operations, providing a technical reference for mining similar types of deposits.