Recent innovations in medical imaging technology have placed molecular imaging techniques at the forefront of diagnostic advancements. The current research trajectory in this field aims to integrate personalized molecular data of patients and diseases with traditional anatomical imaging data, enabling more precise, non-invasive, or minimally invasive diagnostic options for clinical medicine. This article provides an in-depth exploration of the basic principles and system components of optical molecular imaging technology. It also examines commonly used targeting mechanisms of optical probes, focusing especially on indocyanine green-the FDA-approved optical dye widely used in clinical settings-and its specific applications in diagnosing and treating liver cancer. Finally, this review highlights the advantages, limitations, and future challenges facing optical molecular imaging technology, offering a comprehensive overview of recent advances, clinical applications, and potential impacts on liver cancer treatment strategies.© The author(s).