I searched the stackoverflow, and find litte, ask me to install the simulators from Xcode.I think this is not the solution.
Because my other project has the list of simulators.
Compire:
There is no simulators in the Target:
There have whole list of simulators in my other project:
So, I don't think this is Xcode's cause, where is the issue make my first project no simulators?
Make sure your Application deployment target is lower than the iOS Simulator version.
For deployment target check:
For example, if your iOS Simulator version is 10.0 make sure that deployment target is lower than 10.0.