The Mg1-xNa2xWO4 (0 ≤ x ≤ 0.14) microwave dielectric ceramics were prepared through traditional solid-state reaction and sintered at 875−925 °C for 4 h. Compared with pure MgWO4 ceramic, the samples with substituting Na+ for Mg2+ could be sintered at a lower temperature, the quality factor values and the densification of microstructure were obviously improved. Raman spectroscopy proved that the relative permittivity was related to the multiple phases and molecular polarizability. In addition, the distortion of[MgO6] octahedron also changed, resulting in resonance frequency temperature coefficient varied nonlinearly from x = 0 to 0.14. Considering the applications of low temperature co-fired ceramics technology, the Mg1-xNa2xWO4 (x = 0.06) ceramic sintered at 875 °C had the best performance. Not only did it have excellent microwave dielectric properties of εr = 10.474, Q × f = 45,868 GHz, and τf = −69 ppm /ºC, but also presented great chemical compatibility with the commonly used Ag electrode.