After the fall of al-Bashir’s regime in 2019，a coalition of the military and civilian officials dominated Sudan’s political transition. On October 25，2021，the Sudanese military staged a coup to dissolve the civilian-led cabinet，marking the dissolution of the military-civilian ruling coalition. The October 25 Coup was the result of the competition between the military and the civilian for the dominance of the transition process，which had a great impact on Sudan’s politics and diplomacy during the transition period. In terms of internal affairs，the coup has broken the fragile power balance of the military-civilian ruling coalition，and the two parties have seriously opposed each other on the issue of power resharing. The political situation has afterwards shown the characteristics of fragmentation and stalemate，and the democratic transition process in Sudan has emerged a lot of uncertainty. Diplomatically，the coup brought the process of normalizing relations between Sudan and the USA to a standstill，which in turn hampered the westward shift of Sudan’s diplomacy. At the same time，the military tendency of Sudan’s diplomacy gradually deepened after the coup，the junta’s relations with traditional allies such as Russia，Saudi Arabia，and the United Arab Emirates have remained stable after the October 25 Coup. The United Nations，the AU and IGAD are the main mediators in the current political crisis in Sudan and they have formed a coordinated Tripartite Mediation Mechanism. However，the Tripartite Mechanism has not yet played a practical role due to the different objectives and appeals of the Sudan’s related parties.