###### Abstract
[PERSON] and [PERSON] [7] used MS monitoring techniques to determine the excavation disturbed zone (EDZ) of tunnels and set up engineering barriers to prevent fluid seepage through granite fractures in the tunnels. [PERSON] et al. [11] employed MS monitoring techniques to assess the process of increasing oil and gas productions during hydraulic fracturing. [PERSON] [12] examined the geochemical reactions caused by carbon dioxide in underground reservoirs and their possible impact on the mechanical properties of the reservoirs and MS events. China has only recently started researching and applying MS monitoring. In particular, the Mentougou mine was the first to employ MS monitoring in 1959 [13] to keep track of rock bursts. MS monitoring has been widely promoted and applied to assess the stability of the rock surrounding mines since mining areas now face a variety of safety issues as the mining industry develops [14; 15; 16; 17]. For example, [PERSON] et al. [14] applied MS monitoring in the Dongguashan mine and employed moment tensor theory to study the failure mechanism of the surrounding rock. [PERSON] et al. [15] introduced MS monitoring in the Huijahe coal mine in the Binchang mining area, Shaanxi, and proposed a comprehensive warning model for rock bursts based on the MS precursor indicator system. Southwest China has seen a recent increase in the construction of hydropower stations at various locations, aiming to support national development. The hydropower industry has steadily used MS monitoring as a new approach to ensure construction safety in light of the challenging geological conditions and frequent occurrences of various engineering and geological disasters. [PERSON] et al. [18; 19] applied MS monitoring at the Jinping-II hydropower station to study MS events, TBM boring, and the occurrence of rock bursts, as well as to predict the occurrence of rock bursts during TBM boring in deep tunnels. [PERSON] et al. [20] obtained source data from an MS monitoring system and applied the loading/unloading response ratio theory to predict the slope failure during water storage at the Dagangshan hydropower station. [PERSON] and his team [21; 22; 23; 24; 25; 26] introduced MS monitoring for underground caverns of the Houziyan hydropower station and the Shuangjiangkou hydropower station and carried out extensive research on the identification of damages to the surrounding rock, the assessment of the stability of the surrounding rock,and risk warning and prediction during the construction period. [PERSON] et al. [27] used microseismic monitoring technology to obtain microrupture information of the rock mass and compared borehole imaging results to clarify the mechanical behavior mechanism of the rock mass, implying that the macroscopic deformation or failure characteristics of the surrounding rock are directly related to the evolution of microfractures. Although the microseismic characteristics of individual high geostress environments are mentioned when domestic and foreign scholars study the microseismic monitoring of high geostress underground caverns, there are few articles that systematically summarize the microseismic characteristics of high geostress underground caverns. This paper outlines our research on the underground caverns of the Shuangjiangkou hydropower station on the Dadu river. Specifically, an MS monitoring system was constructed to monitor the excavation process of the underground caverns under high geostress. Additionally, the spatial and temporal evolution characteristics of the MS events were analyzed in the rock mass of the underground caverns that are subject to high geostress. The main damage areas of the underground caverns were delineated. The intrinsic connection between the MS activity of the underground caverns and the site conditions was explored. Moreover, a 3D numerical model of the underground caverns was created to reveal the deformation characteristics of the rock mass, and the results were compared with those obtained from the MS monitoring.