Abstract: Quality by design(QbD) is a method based on principles of science and quality risk management, which plays an important role in drug design and manufacturing. With the innovation of preparation technology, pharmaceutical preparations are developing in the direction of complexity, efficiency and individuality. In the development of high-end pharmaceutical preparations/drug delivery systems,the implementation of QbD still encounters many challenges due to the complexity and variability of formulations and the researchers' lack of experience. Combined with the cases, the main elements, implementation steps and auxiliary tools of QbD are introduced, aiming to strengthen the understanding of QbD process and tools. In addition, the application and advantages of QbD in the development of sustained and controlled release preparations, nanomedicine and biotech products, as well as the development of analytical methods, are introduced.Foreseeably, QbD will also play an important role in the development of high-end pharmaceutical preparations, and will ultimately bring greater benefits to manufacturers, regulatory agencies and patients.