Abstract: CdZnTe is an excellent candidate for high efficiency, high-resolution room-temperature nuclear radiation detectors, which are being widely used in environmental monitoring, medicine,industrial non-destructive testing, security inspection and space science. The working principle and performance evaluation of CZT detector were first described briefly.And then the relationship between the CZT crystal physical properties and the CZT detector performance was discussed. The CZT detector simulation and design methods were presented. For promotion of the application and development of the CZT detector, the studies on high-quality, low-cost CZT crystal growth technology, CZT detector design and fabrication and the radiation detection system should be enhanced.