Final optics assembly (FOA) is one of the most important parts in high-power laser facilities. The FOA primary functions include frequency conversion, focusing, wavelength separation and diagnostic beam sampling, which can be realized through optimized FOA optical and structural design. Such a design can meet the basic requirements of high-power laser facilities for different experiments. However, laser-induced damage of final optics and several nonlinear effects resulting from high intensity ultraviolet (UV) laser pulses are major concern during FOA design, construction and operation. This paper reviews the development process of FOA in high power laser facilities, analyzes the core consideration, and discusses the main solution in FOA design.