Application of modern space geodetic technology,especially satellite synthetic aperture radar interferometry,can obtain high-precision,high-spatial resolution coseismic and interseismic deformation data,providing unprecedented opportunities for the study of crustal deformation and earthquake mechanisms. This paper introduces Bayesian inversion method for inversion of parameters of fault dislocation model by using geodetic observations. Coseismic displacements obtained by GNSS and InSAR before and after the 2008 Wenchuan Earthquake were used to invert the geometric parameters of the earthquake fault and the distribution of displacements. The results of the study show that the fault slip of Wenchuan earthquake is mainly concentrated in shallow parts of the fault with steep dip angle,and includes both thrust and dextral components,with the maximum thrust slip of 6.1m and the maximum dextral slip of 6.5m respectively. The forward modelling of coseismic displacements shows that the coseismic deformation at the upper block of the fault is significantly less than that at the down block,suggesting a significantly unsymmetrical mode.