In this paper, Cd-doped β-Zn4Sb3 crystal with space group R3¯c was prepared using the NaCl-flux method according to the stoichiometric ratio of Zn4.1Sb3(NaCl)7Cdx (x = 0, 0.05, 0.1, 0.15). Electron probe microanalysis results showed that Cd and Na atoms were introduced into samples. The transmission electron microscopy and the corresponding area electron diffraction showed that the β-Zn4Sb3 samples prepared by NaCl flux method were of high quality and density. X-ray photoelectron spectroscopy results showed that the valence states of Zn, Cd, and Na were +2, +2, and +1, respectively. All the samples were p-type semiconductors with carrier concentration ranges from 18.61 × 1019 to 9.04 × 1019 cm−3. The thermal conductivity (κ) of the sample decreased with the increase of Cd content. Eventually, the maximum dimensionless figure of merit(ZT) value obtained 1.51 at 690 K for the β-Zn4.1Sb3(NaCl)7Cd0.1 sample, which is higher than that of the Bi-doped β-Zn4Sb3 samples(∼ 1.09 at 673 K) and Te-doped β-Zn4Sb3 samples(∼ 1.08 at 680 K). The findings provide a feasible insight toward understanding the effect of the Cd atom on the crystal structure and thermoelectric properties of β-Zn4Sb3.