After querying, I learned that this is because the module needs to be explicitly imported in the new version of werkzeug.
Add the following code to the error file (here is werkzeug/init.py) to solve the problem.
from werkzeug.utils import cached_property
Remark:
File path under CentOS system: /usr/local/lib/python3. 7 /site-packages/ werkzeug File path under Ubuntu system: /usr/local/lib/python3. 6 /dist-packages/ werkzeug File path under MAC system: /usr/local/lib/python3. 7 /site-packages/werkzeug
end!