Abstract: On June 16, 2021, an M_L3.6 earthquake occurred at the Shuangfengsi reservoir in Chengde City, Hebei Province, breaking the relatively calm record of no earthquakes with a magnitude greater than 3.0 in the Chengde area for many years. To strengthen the seismic monitoring capacity of the reservoir area, a seismic monitoring network for the Shuangfengsi reservoir was constructed. The monitoring network consists of five stations, including three fixed stations and two mobile stations, spread in all directions around the reservoir and along the Shuangtashan-Shuangfengsi fault. The reservoir network includes a monitoring system and a data processing system. This study evaluated the seismic performance, station base noise, and theoretical monitoring capabilities of the five stations within the system. The results show that the newly built network meets the requirements and has certain monitoring capabilities: First, the monitoring scope covers the key areas of the reservoir. Second, the monitoring data are accurate and reliable, enabling strong support for earthquake warning and emergency response. Third, the monitoring system is stable and reliable and can operate continuously and stably. After trial operation and debugging, the seismic network successfully achieved real-time monitoring of seismic activity in the reservoir area, effectively improving the safety and prevention capabilities of the reservoir. Moreover, the data processing results indicate that the newly added stations improve the seismic monitoring capabilities in the Chengde region.