Abstract: Secondary hypertension, accounting for approximately 5%–10% of hypertensive patients, has a complex etiology primarily categorized into renal and endocrine causes. The renin-angiotensin-aldosterone system (RAAS) and adrenal-related indicators play a central role in its screening, diagnosis, and management. This article systematically reviews research advances from the past five years regarding RAAS and adrenal-related biomarkers in the diagnosis and treatment of secondary hypertension, compares screening strategy differences between Chinese and international guidelines, and incorporates emerging technologies such as steroidomics and artificial intelligence. Furthermore, it anticipates a paradigm shift from “empirical screening” toward a “multidimensional precision” approach, with the aim of providing evidence-based support for optimizing the clinical pathway for secondary hypertension in China.