Abstract: Hepatectomy remains the cornerstone of treatment for liver malignancies. However, posthepatectomy liver failure (PHLF) continues to be a major cause of perioperative mortality and significantly impacts long‑term prognosis. With the expansion of indications for hepatectomy and the increasing performance of complex liver resections, accurate assessment of the future liver remnant (FLR) function has become crucial for preventing PHLF. Traditional liver function assessment methods, such as the Child‑Pugh score and the indocyanine green (ICG) clearance test, primarily focus on global liver function and struggle to accurately reflect the functional status of the FLR. In recent years, functional imaging modalities and intraoperative real‑time quantitative function tests have demonstrated significant value in evaluating FLR function. Specifically, the intraoperative ICG clearance test, by simulating postoperative hemodynamic conditions, can more accurately predict the risk of PHLF and provide real‑time functional guidance for surgical decision‑making. The authors systematically review the current status and advancements in FLR function assessment, focusing on the application value of intraoperative ICG‑R15 in hepatectomy and its predictive capacity for PHLF. The aim is to provide a more precise strategy for clinical liver function evaluation, ultimately reducing postoperative complication rates and improving patient outcomes.