Line 2: Take bus No.603 (Yuquan Road North Exit-Caoqiao Village) from Majiapu Community, then transfer to bus No.319 (formerly 320) in ganjiakou, and arrive at the National Library. It is about 18.66 km.
Line 3: Take Bus No.833 (Beiyuan Light Rail Station-Jiayuan) from Majiapu Community, and transfer to Bus No.319 (formerly No.320) in ganjiakou to reach the National Library. It is about 23. 18km.
Route 4: Take No.368 (Dinghuiqiao-Zuo 'an Road) from yangqiao, change to Yuntong 106 (Tamura-Beigongmen) at Balizhuang (Haidian District) and arrive at the National Library. About 26.74 kilometers.
There are many more, but I don't think it is very convenient!