Introduction: The ability of salt-processed Alismatis Rhizoma (SAR) (Alisma plantago-aquqtica L.) to nourish Yin and promote urination is stronger than that of Alismatis Rhizoma (AR). However, there are few studies focused on evaluating the quality of its medicinal materials. Objectives: This study aimed to identify potential quality markers (Q-markers) for SAR, thereby providing a more reliable basis for its quality control and clinical application. Methods: Q-markers were identified through fingerprinting and chemical pattern recognition analysis of 15 batches of SAR. The diuretic effects of these markers were then verified by network analysis and molecular docking. Results: HPLC fingerprints of 15 SAR batches were established, with similarity analysis showing values > 0.85 (0.852–0.990). Chemical pattern recognition identified six critical compounds contributing to SAR quality: alisol F, alisol C 23-acetate, alisol A, alisol A 24-acetate, alisol B 23-acetate, and an alisol O isomer (VIP > 1.0). Network analysis revealed 76 overlapping targets between these compounds and diuretic-related diseases, with core targets including non-receptor tyrosine kinase (SRC), epidermal growth factor receptor (EGFR), mitogen-activated protein kinase 1 (MAPK1), which were identified through protein–protein interaction (PPI) network analysis, with degrees of 27, 24, and 22, respectively. Key pathways involved were the EGFR tyrosine kinase inhibitor resistance pathway, calcium signaling pathway, tumor necrosis factor signaling pathway, etc. Molecular docking confirmed strong binding interactions between the Q-markers and the hub targets, particularly alisol B 23-acetate with MAPK1 (−60.10 kcal·mol⁻¹) and alisol A 24-acetate with EGFR (−46.14 kcal·mol⁻¹) and SRC (−48.86 kcal·mol⁻¹). The diuretic effects of SAR are likely mediated through anti-inflammatory actions and regulation of water–sodium balance via multi-target and multi-pathway mechanisms. Conclusion: This study provides a robust foundation for quality control and clinical application of SAR, though further in vivo validation is warranted.