xcode is too heavy compiled each time you type characters

I am using xcode8.
I'm developing a larger project, but every time I type or delete a single character in the source code, the compilation starts, and it's too heavy for me to find any candidate methods.

It is normal to compile in real time and display errors in real time, but
In my case, the compilation starts to move the progress bar at the top, and in the meantime, there will be no method candidates for about 10 seconds.
(Even if you type characters in the first place, they can be very heavy, such as being reflected on the screen a few seconds later.)
Even if you wait 10 seconds, you will almost always be in this state every time you manipulate a character.

Is there a way to deal with this?
We are deleting the cache log.
There is no problem with specs and memory.