The Hall of High Heaven locates in the imperial city of Beijing in the Ming and Qing dynasties. Built during the reign of Jiajing in the Ming Dynasty, it has been a Taoist temple exclusive to the royal since the Ming and Qing dynasties. The main beam (original Ming Dynasty nanmu) on the first floor's south side has become a significant potential risk and should be replaced according to the relevant technical requirements. As designed, the main beam is structurally reinforced with a specific method after the ideal test data of the reinforcement measures come out from all-round tests and reinforcement measures such as isometric model reinforcement tests. In this way, the beam was saved, and its life was extended. It has been 14 years since the completion of the reinforcement, and no obvious deformation has occurred since the testing. So, the reinforcement program has achieved good results.