使用中国数字地震台网记录的区域和远震宽频带波形，通过频率域和时间域多步反演，研究四川芦山 4.20 Ms7.0地震基于点源模型的震源机制解和有限断层模型。考虑到使用不同波形资料类型、盆地效应以及简化的一维速度模型等因素给反演震源参数结果带来的影响，经过大量测试比较，结果表明：使用区域波形和本区域简化一维速度模型，波形拟合误差最小。此次地震发震断层面参数分别为走向214°/倾角47°/滑动角96°，表现为一次高倾角的纯逆冲型事件。矩心在水平方向上位于震中(东经102.988°/北纬30.303°)偏南西向约4.5 km,最佳波形拟合矩心深度约17 km。平均总标量地震矩M₀为1.16×10¹⁹ N·m，换成矩震级Mw约6.6。推断此地震大多数能量主要在震源偏南西约4.5 km处释放。

We employ multistep inversions in the frequency or time domain, to infer the point-source and finite-fault model of the April 20 Ms7.0 Lushan, Wenchuan earthquake, mainly using regional and far broadband seismic waves recorded by the Chinese Digital Seismic Network. We take into account some factors, which could bring possible effects on the inverted result, consisting of different datasets, basin effect and simplified 1-D velocity models. The result indicates the misfit between observed waves and synthetics is better, if we use the regional waves and the 1-D velocity model in this studied area. This event occurs on a true rupture plane(strike=214°/dip=47°/rake=96°)，showing a high-angle thrust faulting. The horizontal centroid locates at nearly 4.5 kmsouthwest of the epicenter (30.303°N/102.988°E), and the best-fitting centroid depth is about17 km. The total scalar moment M₀, is retrieved with an average value of 1.16×10¹⁹ N·m (or moment magnitude Mw6.6). We speculate that most of energy could release at nearly4.5 kmsouthwest of the epicenter.