Wire-line core drilling technology significantly improves geological core drilling efficiency, yet it frequently encounters borehole deviation during deep-hole operations, which severely compromises construction progress and geological analysis accuracy. This study systematically analyzes the causes and detrimental effects of borehole deviation encountered at a specific mining site, proposing preventive measures including optimized drill tool design, adjusted process parameters, and strict alignment control of drill pipes to effectively mitigate deviation. Field applications demonstrate that these measures successfully reduced abnormal rotational resistance and obstruction of inner tube insertion, ensuring smooth deep-hole drilling operations. This research provides practical guidance and engineering references for controlling borehole deviation in wire-line core drilling applications.