The Advanced Space-based Solar Observatory (ASO-S) was launched with the CZ-2D rocket at 07:43:55 Beijing time on October 9, 2022, opening the era of comprehensive solar space observation in China. The ASO-S mission was proposed by Chinese solar community in 2011. With the support of the “Strategic Priority Research Program of Space Science” of Chinese Academy of Sciences (CAS), ASO-S underwent Phase-0/A, Phase-A/B and comprehensive demonstration. At the end of 2017, it was formally approved by CAS. The scientific objectives can be summarized as '1M2B'. Here, '1M' stands for magnetic field while '2B' for the two major eruptive phenomena (bursts) on the Sun: solar flares and coronal mass ejections (CMEs). ). The mission aims at exploring connections among solar magnetic field, solar flares, and CMEs.