Find the mkspecs folder under the QT installation directory, find the corresponding version compiler you are using, and open qmake. conf. Wait a moment:
/MD: dynamically links multi-threaded libraries (msvcrt. Lib ). When using this option, you must use the/nodefalib lib option to ignore the libc. Lib, libcmt. Lib, libcd. Lib, libcmtd. Lib, and msvcrtd. Lib libraries; otherwise, a link error occurs;
/MDD: dynamically link the multi-thread debugging Library (msvcrtd. Lib ). When using this option, you must use the/nodefalib lib option to ignore the libc. Lib, libcmt. Lib, msvcrt. Lib, libcd. Lib, and libcmtd. Lib libraries; otherwise, a link error occurs;
/MT: static link multi-threaded Library (libcmt. Lib ). When using this option, you must use the/nodefalib lib option to ignore the libc. Lib, msvcrt. Lib, libcd. Lib, libcmtd. Lib, and msvcrtd. Lib libraries; otherwise, a link error occurs;
/MTD: static link multi-thread debugging Library (libcmtd. Lib ). When this option is used, you must use the/nodefalib lib option to ignore the libc. Lib, libcmt. Lib, msvcrt. Lib, libcd. Lib, and msvcrtd. Lib libraries. Otherwise, a link error occurs.