Abstract: To determine the rupture processes of big earthquakes is a fundamental problem of earthquake studies, which also supports earthquake physics research. Although the joint use of seismic, geodetic and seismicity data provides good constraints to determine the fault plane information of inland earthquakes, it is still challenging to unveil non-planar fault planes for oceanic earthquake ruptures. For complicated earthquakes, that ruptured more than one fault plane, a method to stably obtain focal mechanism changes is required to determine the fault plane information precisely. In this study, we analyze the stability and flexibility of multiple seismic methods, i.e. back-projections, multi-point-source inversion and finite fault inversion, to determine the rupture kinematics of big earthquakes, and find the stability spatial-temporal resolution and flexibility to resolve focal mechanisms that are not compatible in each single techniques. A sequential strategy is thus proposed to use back-projection results to prescribe the a priori information of multi-point-source inversion to achieve mechanism changing point source solutions with high spatial-temporal accuracy. Two strategies to connect these two techniques and other technique concerns are also discussed.