Qt5.12 + vs2019 cannot locate the program input point in the dynamic link library

Environmental Science ：qt5.12.2 + vs2019
System ：win10
Error is reported during operation ：

terms of settlement ：
1. Add system environment variable
Click on My computer -> Right mouse button properties -> Advanced system setup -> environment variable -> find “ System variables ” Under the “PATH”-> Check edit -> newly build
The first environment is MSVC download QT When you choose MSVC route
The second environment is MinGw download QT When you choose MinGw route

a key ： The order of these two cannot be reversed , must MSVC on top , Otherwise, it cannot be read successfully dll file