6 digits after the certificate or 999999. The password of the library card applied before May 18, 2009 (excluding May 18) is the last six digits of the number of the certificate (such as ID card and military officer's card) at the time of application; The password of the library card after May 2009 18 (including 18) is 999999. Zhejiang Library is one of the earliest provincial public libraries in China. The main library is located in Xihu District, Hangzhou City, Zhejiang Province. It is a national first-class library and the first batch of national key protection units of ancient books.