With strategic objective of serving national information security, the construction goal of the "Beijing-Shanghai Backbone" project is to build quantum secure communication backbone line for connecting Beijing and Shanghai, via Jinan, Hefei and other places, running in a total length of more than 2,000 kilometers. It connects metro area access networks of various cities, creates wide-area optical fiber quantum communication network, and builds large-scale quantum communication technology verification, application research, and application demonstration platform.