将S变换时频分析技术引入微震信号波形分析领域，通过震源破裂尺度，研究微震信号频率特征与岩体变形破坏之间的联系。以西南地区3个水电工程作为研究对象，将大量微震监测数据作为统计样本以减小外部因素对参数计算的影响。在该基础上统计、分析岩体破裂尺度与微震信号频率之间的关系，结合大渡河猴子岩水电站地下厂房微震与多点位移计监测资料进行工程实证研究。研究结果表明，当岩体破裂尺度增大时微震信号高频成分减少，表现出低频特征；在围岩变形过程中微震信号高频成分呈现出先减少再增加的演化规律，围岩发生明显变形前微震信号出现由高频向低频转移的现象，因此，可将聚集区域内微震信号频率降低作为该区域岩体宏观变形破坏的前兆信息。研究结果可为基于微震监测的岩体工程稳定性分析及其灾害预测预报提供参考。

The S transform(ST) time-frequency analysis technique is introduced to microseismic signal analysis field; the correlation between rock deformation-failure and microseismic signal frequency characteristics is investigated based on fracture scale. A large-scale seismicity observation is carried out in three hydropower engineering in Southwestern China; a significant amount of data is used as the statistical samples to minimize the influence of external factors on parameters calculating. Based on the statistical samples, the correlation between the source fracture scale and the frequency characteristics of microseismic events is analyzed. An engineering verification research is carried out combining with the monitoring data of microseismicity and multipoint extensometers in Houziyan hydropower station underground powerhouse. The research results show that the high frequency components decrease and microseismic signal displays low-frequency characteristic as the fracture scale increase; the microseismic high frequency components decrease at first and then increase during the deformation process of surrounding rock; and the frequency of microseismic events shifts from high band to a lower one before deformation. It can be believed as precursory information of deformation-failure that the frequency of microseismic events in concentrated area starts to decrease. Results can provide references for the stability analysis and hazards prediction of rock engineering based on microseismic monitoring.