Although 7zip does not support DEB format directly, you can extract the contents of a 7-zip archive using the program and then repack the data to DEB format in some other. However, such *.deb files won't ever work as installation packages in Debian.
Convert 7-ZIP compressed 7z archive to Debian Linux package.
We have found 2 software records in our database eligible for .7z to .deb file format conversion.
Microsoft Windows software - convert 7z to deb on Windows
Popular open source file archiver with a high compression ratio
Convert from 7z file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned 7z to deb. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Apple macOS / Mac OS X software - convert 7z to deb on OS X
Full-featured compressed archives manager