Combine all objects into one UV-map?

Hey I have separate objects now on my scene and I have uv map all the objects now I want to combine all UV-maps into One, How do I do that?

There are numerous ways.The way I do it is to add seams to your objects, join them into one mesh, UV unwrap, adjust UV layout as required then split them out again into their separate objects (select all vertices / P / separate objects)