Abstract: The rapid expansion of mega-constellations has not only degraded the environment of outer space but also exacerbated tensions among countries competing for limited resources. Against the backdrop of long-term sustainability of outer space activities, the sustainable use of satellite frequency spectrum and orbit resources has attracted much attention, making the establishment of a reasonable allocation mechanism for such satellite resources particularly important. The "Milestone" and the "Post-Milestone" rules (also referred to as the “milestone reporting rules”) were successively adopted at The World Radiocommunication Conferences (WRC) of 2019 and 2023, with the aim of curbing the chaos in outer space and strengthening supervision over satellite constellations. The Milestone rules redefine the criteria for the "Bring into Use" (BIU) of satellites and establishe a milestone-based approach to regulating the subsequent deployment of satellites. The "Post-Milestone" rules propose actions to deal with situations in which the number of satellites is decreased after a constellation has reached a milestone process. However, there are still obvious deficiencies in the above rules. To improve the allocation mechanism, the legal nature of satellite frequency and orbital resources should first be clarified. Furthermore, a robust resource sharing mechanism and punitive mechanism should be considered to guarantee the effectiveness of the allocation mechanism, as well as to achieve an equitable, rational and efficient use of such resources.