Subclinical hepatitis B infections often present with low viral loads that are easily missed by routine testing. High-sensitivity hepatitis B DNA testing provides critical technical support for their screening and diagnosis. This article focuses on core clinical application challenges of this testing technology, defining key target populations including post-antiviral treatment cirrhosis patients and high-risk groups with complications. It clarifies differences in inclusion criteria across medical scenarios while establishing unified standards. Based on technical characteristics and clinical evidence, a diagnostic cutoff of 10-2000 U/ml is proposed, along with validation and adjustment strategies for different populations. The analysis examines testing application boundaries, technical limitations, and clinical practice issues, providing actionable evidence to optimize screening processes for subclinical hepatitis B infections, improve diagnostic accuracy, and help reduce progression risks of related liver diseases.