Abstract: HPR1000 adopts the symptom based emergency operating procedures (SEOP) to deal with accidents. In this paper, the related procedures for secondary pipe break accidents in SEOP are studied, including the development of procedures and supporting verification. In the development process of the procedures, a reasonable framework of procedures is constructed, and the operation procedures for different accidents are summarized. Based on the design characteristics of HPR1000, the main recovery strategies and relevant important setpoints are determined. In the supporting verification process, the typical secondary pipe break accidents are selected for analysis. The results show that the mitigation strategy provided by SEOP can effectively guide the nuclear power plant to the required safe and controllable state in time. In addition, by comparing different types of accident procedures, the advantages of SEOP in the coverage of accidents and the timeliness of recovery operation are proved. Through the research of this paper, a reasonable method is established for the development and verification of the operation procedure for HPR1000 secondary pipe break accidents.