The roof will be dismantled in order to repair the leaks, and the large cross on the bell tower will be reinforced and repainted to ensure that it is resistant to decay and termites. Tiles will be replaced with shale slate, and the cathedral's interior facilities will be improved.
Before the work begins, the church will protect its historical relics.
"The church's valuable structures will be protected to preserve its original beauty," said Gu Zhangjun, a diocese priest. "The parts covered by wooden slate are important structures, and we will pay special attention to protecting them."
The cathedral, which attracts visitors from home and abroad, will be unavailable to worshipers and visitors until the final quarter of next year. Tourists are likely to miss the opportunity to walk its aisles.
"I have seen many churches, but there is something special about this one," said Andres Cuevas, 19, from Mexico.
Yan Hongji, 60, a nearby resident, said the square in front of the church has become a popular place for newlyweds to take wedding photos. In addition to being a religious site, "young people regard it as a sacred place to celebrate their love", he said.