Druggability evaluation is one of the core processes in new drug development, yet the inaccuracy and high cost of existing in vitro liver models have been a major technical bottleneck, leading to an increasing demand from the pharmaceutical industry for reliable in vitro liver models to enhance the efficiency of new drug research and development. Traditional animal models and in vitro 2D culture models have their limitations in simulating in vivo physiological and pathological conditions, making it challenging to accurately predict drug efficacy and safety. With the advancement of microfluidic technology, in vitro cell culture, and biosensor technology, liver-on-a-chip (LOC) has garnered increasing attention in the field of new drug development in recent years, and is expected to become a powerful tool for addressing the challenges in druggability evaluation. While introducing the construction technology of LOC, this article mainly summarizes the research and application of existing LOC from the perspectives of disease model construction, drug metabolism research, and drug safety evaluation. Furthermore, it analyzes the role of LOC in druggability evaluation and discusses the current challenges and prospects in this field.