CdZnTe wafer is an ideal substrate for HgCdTe epitaxial thin films. In order to optimize the electrical contact performance of CdZnTe substrate， the Au/Cd composite electrode was prepared on p-type （111）B CdZnTe wafer （tellurium-rich surface） by vacuum evaporation and magnetron sputtering respectively. By means of contact adhesion test， the adhesion between Au/Cd electrode and CdZnTe substrate was studied. Rutherford Backscattering Spectrometry （RBS） was used to compare the element depth distribution of samples with different deposition methods. The effects of the two preparation processes on the ohmic contact characteristics of Au/Cd composite electrode and CdZnTe substrate were compared through the current-voltage （I-V） test， and the optimum preparation technology of composite electrode was obtained.