The characters combine literally to mean “Talent (才) and appearance (貌) are both (双) complete (全).”
In Chinese culture, there has long been an appreciation for balance and completeness. The idiom 才貌双全 reflects this value, celebrating a person who embodies both internal and external excellence. Historically, it was a high ideal for women, often used in classical literature to describe heroines who were not only beautiful but also skilled in poetry, music, or strategy.
While rooted in tradition, 才貌双全 is still very much in use today, though its context is important.