QT4 has no pre-compiled 64 bit VS version. When compiling projects with qt4 in 64 bit mode, there will be a linking error for the incompatible library, such as Qtgui4.lib. As there is nowhere to download such outdated qt4 precompiled version for VS (Qt 5 is supported in 64 bit), so the only way is to build by myself.

Download from https://download.qt.io/archive/qt/4.8/4.8.6/

qt-everywhere-opensource-src-4.8.6.tar.gz

Decompress

Open VS 64 bit command tool in software installation tools

Enter the Qt directory

configure -platform win32-msvc2010 -opensource -fast -qt-style-windowsxp -qt-style-windowsvista -no-qt3support -qt-sql-odbc -no-phonon -no-phonon-backend -no-script -no-scripttools -no-multimedia -nomake examples -nomake demos
nmake
nmake install

The compilation takes up to hours