As far as I know, from 2008 to now, Shanghai Library has the largest collection of books, with a conservative estimate of more than 55 million volumes and pieces.

The top ten libraries in China are Shanghai Library, Nanjing Library, Shandong Library, Zhejiang Library, Tianjin Library, Hubei Library, Shanxi Library, Chongqing Library, Hunan Library and Gansu Library.

I hope the answer will help you! ^_^