Open Xcode -> Preferences -> Components -> Simulators from the Xcode menu bar and download the corresponding version of the simulator.
Since the files related to the simulator are large and take a long time to download, you need to wait patiently. After the download is completed, the download button in front of the corresponding version of the simulator will change to a download completed style.
Click Window -> Devices on the Xcode menu bar, and then you can see the device list. However, under the simulator list (SIMULATORS), you cannot see the iOS8.1 version of the simulator.
Then click the plus sign in the lower left corner to add the simulator. First select the simulator device (Device Type), then select the system version (OS Version), then give the simulator a name, click Create, and the addition is successful. Simulation The simulator just added is now in the simulator list.
After adding the target simulator, you need to close Xcode and restart it (or restart the computer), then open your project, select your new target simulator, and then you can run it on your target simulator.
PS: I added the 8.1 simulator here and still can’t see it after restarting. The reason is that my adaptation version is 9.0. You can see it after changing it to 8.1. .