The MgTiTa2O8 ceramics were synthesized in the molten salt KCl. We have conducted an examination of the phases, microstructure, and microwave dielectric characteristics of MgTiTa2O8 ceramics. This investigation involved the use of X-ray diffraction (XRD), Rietveld refinement, and scanning electron microscopy (SEM). The result demonstrated that MgTiTa2O8 ceramics exhibited crystallization into a tri-rutile structure with space group P42/mnm (136). With the increase of temperature, the relative density gradually increases, which benefit the dielectric constant and Q × f value. However, as the temperature continues to rise, there is a decrease in the εr and Q × f value, which can be ascribed to over-sintering of the sample and a resultant reduction in the uniformity of grain size. The correlation between oxygen octahedron distortion dielectric, bond strength, packing fraction, and properties of microwave is discussed. The Q × f value increases with the increase of atomic packing density. The value of τf decreases with the increase of bond energy and has no direct relation with the distortion of oxygen octahedron. The MgTiTa2O8 ceramics sintered at 1150 °C exhibited superior dielectric characteristics of εr = 35.1, Q × f = 32,200 GHz, τf = + 95.4 ppm/°C.