Abstract: Firstly, an overview about the development of the China Trajectory Optimization Competition (CTOC) and the research background of the problems put forward in the 12th edition of CTOC was briefly introduced. Then, the two sets of competition problems, “Mars migration supported by the reusable Earth-Mars-cycling stations" and “near-Earth asteroids exploration supported by the reusable probes" were briefly introduced and interpreted, the competition organization process was reviewed, and the final results were analyzed. Finally, the academic seminars and discussion after the competition were described, as well as its summary and prospects. In addition, several characteristics that distinguish this competition from other discipline competitions were summarized in this paper.