In this article, we'll walk you through how to boot your Mac into Safe Mode. Safe Mode is a diagnostic mode in which all nonessential programs and services are disabled, allowing you to remove malware or change settings.
Steps

Step 1. Restart your computer
Do this if your computer is on. Open the Apple menu

, and click Restart twice.
- If the computer is off, press the power button
-
Windowspower on its body to turn it on.

Step 2. Press and hold the ⇧ Shift key
Do this as soon as the computer goes to restart.
If you're using a Bluetooth keyboard, press ⇧ Shift after you hear the computer start-up sound (or immediately after the Apple logo appears)

Step 3. Wait for the login screen to appear
This will happen in 1-2 minutes.

Step 4. Release the ⇧ Shift key
When the logon screen appears, the computer should be in safe mode, that is, the ⇧ Shift key can be released.

Step 5. Log in to the system
Select your account and enter your password.
If FileVault encryption is enabled on your computer, log in first and then unlock your startup disk

Step 6. Fix the problems
If you have problems with the startup sequence or system operation, see if they are present in safe mode. If not, the problem might be with one of the programs.
If the problem still occurs, it is caused by the computer hardware, system, or core programs

Step 7. Remove programs from startup
In safe mode, remove any problematic or resource-intensive programs from startup. This will help speed up system boot.
You can also uninstall unnecessary programs in safe mode

Step 8. Restart your computer to exit safe mode
To do this, open the Apple menu

, click Restart and follow the instructions on the screen. The computer will boot normally.