All versions of QT download address :
http://download.qt.io/archive/qt/
qt-opensource-windows-x86-5.14.1.exe --2.3G can be installed.
Open the installation file and click Next as prompted
Others for reference:
All Qt Creator download addresses:
http://download.qt.io/archive/qtcreator/
Download address of all Qt VS development plug-ins:
http://download.qt.io/archive/vsaddin/