Low-temperature co-fired ceramics technology (LTCC) exhibits enormous superiorities in packaging, integration, and interconnection. However, the complex compositions of low-melting point sintering aids may react with ceramic matrix, which increases the difficulties of phase control and tape casting. In this work, the Li 2 CO 3 -B 2 O 3 -Bi 2 O 3 -SiO 2 (LBBS) sintering aid was adopted to sinter ZnZrNb 2 O 8 ceramics with single phase at low temperatures. The LBBS glass could be used to fabricate pure-phase ZnZrNb 2 O 8 ceramics at a low sintering temperature, promote the grain growth, and increase the densification of ZnZrNb 2 O 8 ceramics. Furthermore, the unit cell volume, NbO 6 octahedral distortion, Raman shift, and FWHM changed along with LBBS addition, thereby affecting the microwave dielectric properties. Remarkably, ZnZrNb 2 O 8 ceramics doped with 0.75 wt.% LBBS at 950 • C were chemically compatible with the silver electrode and exhibited excellent microwave dielectric characteristics: ε r = 27.1, Q × f = 54 500 GHz, and τ f = −48.7 ppm/ • C, providing candidates for LTCC applications.