在搜集和整理中国地震局四川数字地震台网2001年1月—2013年7月震相观测报告的基础上,采用单台多震和达测定法,重点分析研究了芦山地震前波速比时空变化特征.为保证计算结果的可靠性和稳定性,对所收集到的单台震相数据和计算结果的精度进行系统的筛选和限定,同时对出现异常的地震台,进行不同台站方位和距台站不同空间范围的波速比时空变化特征的分区细化对比研究.根据其存在的共性和差异,探讨预测孕震体空间尺度的可能性.结果发现,龙门山断裂带南段及附近地区的小金、蒙顶山、油罐顶、花马寺和五马坪等5个台站的波速比在芦山地震前均存在较明显的降低过程;小金、蒙顶山、油灌顶和花马寺等4个台站的波速比异常降低过程大约持续了3年半,震前除小金台未见明显回返过程外,其它3个台站均在震前1年左右出现回返特征;峨眉山台和五马坪台的波速比时间演化特征差异性较大,表现出一定的复杂性.从芦山地震前波速比时间变化特征的动态跟踪中还发现,强震前波速比异常区的范围具有向未来震中及其附近地区收缩的趋势. Based on the collection and collation of the seismic observation data from January 2001 to July 2013 of Sichuan Digital Seismograph Network of China Earthquake Administration, the single multi-seismic and up-to-date determination method was used to analyze the spatial and temporal variations of the wave velocity ratio before the Lushan earthquake Features.In order to ensure the reliability and stability of the calculation results, the accuracy of the single seismic phase data collected and the results of the calculation are systematically selected and limited. At the same time, Comparisons of subdivision and refinement of spatio-temporal variations of wave velocity-ratio in different spatial regions of stations were carried out.According to the commonness and difference of their existence, the possibility of predicting the spatial scale of pregnant earthquakes was discussed.It was found that in the southern segment of the Longmenshan fault zone and its vicinity The wave velocities of Xiaoguang, Mengding Mountain, oil tank top, Huamasi and Wumaping stations are all obviously decreased before the Lushan earthquake; Xiaojin, Mengdingshan, Yulinitou and Huamaji etc. The wave velocity anomaly reduction process of the four stations lasted for about three and a half years. Before the earthquake, no obvious return process was found except for the Xiaoguai station. The other three stations all showed return characteristics about a year before the earthquake; the Emei Mountain and the five horses Ping-tai The time-evolution characteristics of wave velocity ratio are quite different and show a certain degree of complexity. From the dynamic tracking of the time-varying characteristics of wave velocity before Lushan earthquake, it is also found that the range of anomalous wave velocity anomalies before strong earthquakes has the potential to propagate to the future epicenter and its vicinity Shrinking trend.