Abstract: The mesh technique was studied in this paper. For the motion of flow field mesh, a novel update method based on mapping structured mesh was presented. In present method, the mapping interpolation function was introduced to obtain the computational displacements of the flow field mesh nodes. The update mesh system for flow field is formed by adding computational displacements to the original mesh node coordinates of flow field. Through a group of the mesh update computation for flow fields around a two dimensional square object, a spindle-like object and a cubic body, it was found that the original topology of a fluid mesh system could be kept and the higher mesh quality and faster computational effect for mesh update could be obtained. Furthermore, the constrained counterforce distribution technique and the projection interpolation approach were proposed to transfer the computational data from a flow field to a structural field and reverse, respectively. Finally, with a series of computation, it was revealed that the better effect for data transfer between the interface of a flow field domain and a structural domain was reached.