We use scattering scanning near field optical microscopy to investigate the near field response of tungsten ditelluride(WTe2). By using finite-dipole model we calculate the scattered signal ratio of sample to substrate and found that it can not be fully described by bulk property. This difference is most likely contributed to the decoupled layer on the bulk WTe2.Then we give possible explanations to the bright fringe at the sample edge. This work provides a reference for the optical research of topological materials in the future.