My phone’s application keep uninstalling themselves and you can’t install them untill you delete them and download again how can i stop this problem?

With so little information, it's hard to tell, but I would recommend that you take a look at the available storage on your device. If you have enough storage available, then do you have "Updates" turned on in Settings>iTunes & App Store>Automatic Downloads? If so, then it is likely that what you are seeing are the updates being applied.

Best,

GB

Again, what do you mean by "uninstall"? If you can delete the app from your device, then the app is still on it. I do not understand the distinction you are making between the two. If it has been uninstalled, then it would no longer be anywhere on your device, so there would be nothing to delete.

GB

Sorry, I'm confused. How can you delete them if they have been uninstalled?

GB