Abstract: Relying on the technical requirements of the independent third-generation nuclear power HPR1000, China Nuclear Power Engineering Co., Ltd., CGN, and Chongqing Materials Research Institute Co., Ltd. successfully developed the primary circuit temperature measuring detector and component engineering prototype, and passed the quality appraisal test of the third-generation nuclear power environmental conditions and realized the product supply. During the development process, technical problems such as key materials, overall structure, manufacturing technology, test verification and performance evaluation were solved.