The nuclear medicine imaging technology represented by PET and SPECT is one of the main means of modern medical imaging diagnosis. It has been widely applied to the fields of cancer diagnosis,cardiovascular disease diagnosis and cranial nerve research. The Gamma ray detectors are the core components of PET and SPECT imaging systems,and the performance of the detectors determines the comprehensive performance and clinical diagnosis value of the imaging system. The current development of the detectors and crystal materials for nuclear medicine imaging system have been studied in this paper,and the development directions of the detector technology for the nuclear medicine imaging are analyzed and predicted.