Thank you for your advice. I have given up using mingw after too many times building failures. I clone the latest source code from the git and change to use MSVC compiler to build and install ITK by Visual Studio 2019 successfully. Now my demo app runs correctly in Qt Creator with MSVC compiler and debugger, instead of mingw. (Considering of cross-platform, I have to use different .pro project file with different compiler.) And it also seems to work smoothly with VTK9.0.1 by using itkVtkGlue. 
P.S. The post you replied (Error in ITK compilation with wingw32-make) is really useful. Thanks!