The invention discloses microwave dielectric ceramics and a preparation process thereof, belonging to the technical field of microwave dielectric materials and manufacture thereof. The microwave dielectric ceramics comprises carbonate, oxide and Na, Gd, Dy, Er, Lu and Ti organic matters, and has a chemical formula of Na0.5Re4.5Ti4O15, wherein Re=Gd, Dy, Er and Lu. The invention provides a novel rare-earth-containing microwave dielectric material, and the selection range of a microwave dielectric application material is enlarged; and aiming at the microwave dielectric ceramics, the invention provides a novel matched process, namely, the microwave dielectric ceramics with better ceramic formation is obtained by combination of a process of preparing a powder material by adopting a sol-gel process and a process of preparing the ceramics by adopting a solid-phase reaction process.