Hi, I'm not sure if here is the best place for such a question. so forgive me if it's not and admin please move it to a better place.
anyway, I want to know if there is any topographic maps of Big mountains (mainly above 7000m which is void data of SRTM project) for GPS devices?

Maybe post a request on GPSfiledepot or gps underground

Yes there is.

If you want to use a smart phone GPS, get Gaia GPS.
It's $20 and very well-designed, with many different map layers.

Several of the map layers are open source worldwide topographic maps.

Here is a short tutorial video on how to use it.
https://www.youtube.com/watch?v=oi4aUEQj7vU