I wanna to make a picture cake at home so anyone tell me how can i make it
You mean with an edible image?
You either have to have a printer that prints edible images or order one.
There are websites you can order from, such as http://www.ediblepictures.net/Pages/CustomEdibleImages.aspx
Or some bakeries will print them for you, I know our Safeway does them for a couple dollars.
Those are really good instructions for applying it.