In order to get the characteristic parameter of gas-solution interface in magnetic field， measurement of deformation was done by the method based on mirror image combined with the structure illumination. The quantitative results of surface deformation were calculated from the phase unwrapping of gray matric and 3D reconstruction. The present experiment demonstrated that the unhomogeneity of surface tension induced by gradient magnetic field near the surface of liquid could lead to surface deformation, the quantity and direction of deformation are directly related to the distribution of gradient filed, and a new way to the research of the kinetics of Buoyant-Thermcapillary Convection is proposed.
