Polo is an ancient activity that reached its peak in the Tang Dynasty under the esteem of the rulers. The costumes specifically applicable to polo activities emerged during this period, which are typical and representative, and an important source for studying ancient sports costumes in China. The modern digital environment provides a new direction for polo costume research. The computer platform creates polo mannequins and costume models, which can restore the dressing effect of polo costumes in the Tang Dynasty, analyze the suitability of costumes and activities, and promote the research process of ancient Chinese sports costumes. Through the analysis on the styles and proportions of polo costumes in the Tang Dynasty, CLO 3D, 3Dmax and Maya are used to digitally and virtually recover the costumes and activity states. With the stress on the costumes during the activities as the research object, the rationality of the structural design of polo costumes during the activities is further verified through the dressing effect and stress evaluation of the costumes. It is concluded that the activity dynamic has an impact on the polo costume wearing form, and the structural design of polo costume different from that of regular clothing has rationality, which provides more space for the human body to swing and hit the ball.