As an essential member of the tangible cultural heritage, historic architectural heritage contains unique historical and social values. This paper describes the current state of conservation of historic buildings and the ways of conservation, revitalization and renewal by the Macao authorities, and draws on the Cathedral of the Merciful Jesus in Goa, India, and Coventry Cathedral in England, to provide suggestions for the conservation and restoration of the site of St. Pauls College in Macao. St. Pauls College is divided into three main parts: St. Pauls Church, the Seminary, and the Fortress, for conservation, revitalization, and renewal. The current conservation and renewal measures of the site are still inadequate. By analyzing the conservation strategies and the current situation, St. Pauls College needs the cooperation of the government and the public to value and improve the reuse value of the site and increase its visibility. At the same time, the use of rich restoration and renewal methods, combined with the current situation of society in the restoration and renewal of the site, can present valuable ideas.