In this paper, (1-x)CaBi2Nb2O9-xNa0.5Bi2.5Nb2O9 [(1-x)CBN-xNBN; x = 0, 0.1, 0.3, 0.5 and 0.7] ceramics were prepared by the traditional solid-state method. The structure and properties of CBN and NBN are very close to each other, and XRD shows that Na/Bi ions have entered the lattice of CBN. By adjusting the content of NBN in (1-x)CBN-xNBN ceramics, the crystal structure of the ceramics undergoes a pseudo-tetragonal distortion that can significantly improve thermal stability. Analysis of the data of XRD refinement confirms there is pseudo-tetragonal phase at x = 0.1 to 0.5. Moreover, the remnant polarization Pr is obviously improved due to the reduction of grain size and pseudo-tetragonal distortion. Although the Curie temperature of the CBN-NBN piezoelectric ceramics decreases, the tanδ at high temperatures is significantly reduced and the DC resistivity is increased. The 0.5CBN-0.5NBN ceramic shows excellent comprehensive properties: d33 of 13.8 pC/N, Tc of 873 °C, tanδ of 2.1% at 500 °C, and Pr of 8.92 μC/cm2, especially the d33 maintains 94.9% of the initial d33 after depolarization at 850 °C, which has competitiveness in the high-temperature piezoelectric materials.