Hi @maziqi96,
Thank you for updating this discussion with your question!
An example of the vtk workflow for loading data into python can be found on the first post of the related form post Loading VTK data into Python.
I also just updated that forum post with an example of how to accomplish the same thing using PyVista, which provides a much more streamlined solution.
Please feel free to follow up with any questions here or on the other forum post!
Cheers,
John