Abstract: This paper introduces a physical feature-sensitive topological simplification algorithm for planar vector fields to solve the physical feature preserving problem ignored by pre-existing methods.Its central idea is to classify the vector field region under the application-specified physical criterion,and combine the feature detection of a vector field with its topological simplification. Through merging the grids over the physically less important subregions and computing new topology skeleton of the vector field defined on this area,a physical feature preserving topological simplification is performed perfectly. Meanwhile,a remarkable data compression is implemented as well.An experimentation study shows that the algorithm will be able to play an important role in feature extraction of complex flow fields.