China's BeiDou navigation system (BDS) has evolved from the demonstration navigation satellite system (BDS‐1) to the regional navigation satellite system (BDS‐2). Now, the global BeiDou navigation system (BDS‐3) is in construction and is proceeding well. The design and functions of BDS‐3 are quite different from those of both BDS‐1 and BDS‐2. In this paper, the general design, the coordinate reference system, and the system time basis of BDS‐3 are introduced. Several new payloads designed to accomplish different objectives are described as well as the platforms on which they are hosted. Since BDS‐3 consists of several different constellations, the general service capabilities and special service functions provided by these different constellations are described. The performances of the initial BDS‐3 platforms are evaluated based on the available eight‐medium Earth orbit (MEO) satellite configuration. The results of satellite orbit determination and prediction with and without the BDS‐3 inter‐satellite links (ISL) are compared and analyzed.