简便方案：只需在代码中引用以下几个模块，封装时Pyinstaller即可自动引用，无需再次手动拷贝。
亲测封装成单文件/非单文件都已成功，省去了要封装成多文件还要往里拷贝的麻烦。我的程序不带这五个dll文件是9MB，如此一来变成23M，也不会再有pyi_rth_qt5plugins错误。
import?ctypestry:temp1=ctypes.windll.LoadLibrary(?'DLL\\Qt5Core.dll'?)
temp2=ctypes.windll.LoadLibrary(?'DLL\\Qt5Gui.dll'?)
temp3=ctypes.windll.LoadLibrary(?'DLL\\Qt5Widgets.dll'?)
temp4=ctypes.windll.LoadLibrary(?'DLL\\msvcp140.dll'?)
temp5=ctypes.windll.LoadLibrary(?'DLL\\Qt5PrintSupport.dll'?)except:
pass