[1] Qt Linguist Manual: Translators | Documentation | Qt Project ( 版) http://qt-project.org/doc/qt-4.8/linguist-translators.html

QM Qt message files

are binary files that contain translations used by an application at run-time. These files are generated by lrelease, but can also be generated by Qt Linguist.

[2] Qt .qm — Translate Toolkit 1.13.0-rc1 documentation ( 版) http://translate-toolkit.readthedocs.org/en/latest/formats/qm.html

A .qm file is a compiled Qt linguist file. In many ways it is similar to Gettext, in that it uses a hashing table to lookup the translated text. In older version they store only the hash and the translation which doesn’t make the format useful for recovering translated text.