Radiation detector is one of the most important components for nuclear medicine imaging equipment like single photon emission computed tomography (SPECT). Among different types of detection technologies, scintillator detectors are the most extensively used ones, but associated with some problems including slow imaging speed and poor image quality which are inherent and difficult to solve. In recent years, the advancement of new semiconductor detection technologies such as cadmium zinc telluride (CdZnTe) detectors have greatly improved the energy and spatial resolving capability of nuclear medicine imaging equipment. Based on the introduction of the working principle and main parts of nuclear medicine equipment, this paper uses the SPECT as an example to review the advancement of the CdZnTe detectors including the performance improvement in clinical nuclear medicine, and finally points out the potential research and development trends of CdZnTe detectors demanded by the nuclear medicine clinical applications.