Fr. Liu Maochun said to be one of 20 clergymen under constant pressure to join government church.
Ceremony near Shanghai sees installation of prelate who succeeded aging bishop three years ago.
Agnes Chow's detention came on same day as sanctions against U.S. lawmakers critical of Chinese policies.
With weeks to go before renewal of Vatican agreement, some say life for the Catholic Church has not improved.
Bishop Cui Tai has been in and out of jail since 2007.
Lockdown allows religious education for young people, which had previously been strictly forbidden.
The Vatican had been sending masks to China since January; now China's faithful return the favor.
After healing the sick in China, these doctors now come to help their Italian counterparts.
It is thought that China's population is now more than 7% Christian
The Communist Party also banned all group religious activities.