The dynamical behavior of fluids,in particular the health monitoring for liquid sloshing in aircraft propellant tank,is the current research focus.In this research a novel method is proposed for monitoring the dynamic deformation of the liquid sloshing surface at different moments based on transmission-lattice based geometric phase analysis.An orthogonal lattice pattern is placed under the tested liquid in a container,some calibration tails are printed on the wall of the container,the phase of the distorted transmission-lattice images and the height information of liquid level are obtained when the liquid surface deformation occurs.