Abstract:We use C++ to apply an inversion method for source rupture of earthquakes on Qt platform based on QSSP software. The algorithm is divided into two stages. The first stage is a global search by heat bath algorithm, which consists of two steps. First, we divide the parameter range according to the initial conditions such as the tectonic background of the fault area. Second, we define random parameters at each range and start the iteration for making the preliminary waveform fitting avoid the local optimal solution. The second stage is a fast convergency by quasi-Newton algorithm, which improves the fitting level of waveform. In this stage, the iteration will stop until the result of objective function is less than the error, and output fits undetermined parameters. In this paper, to avoid the parameter ill-posed problem, we use the Laplace equation to establish the smoothing matrix, and the smoothing factor is introduced to smooth constraint on the fault model. In addition, we use checkerboard model to ensure the stability and reliability of the above method. At last, we reverse the rupture process of the Lushan MS7.0 earthquake on April 20, 2013 using gravity data from 13 gravity stations, and compare with other research.