Could be the preferences are corrupted ..
Go to ~/Library/Preferences. Move the com.apple.Safari.plist file from the Preferences folder to the Desktop.
Quit then relaunch Safari to test. If that helped, move the .plist file to the Trash.
~ (Tilde) character represents your Home folder.
Also, could be a third party Safari addon...Unsupported third-party add-ons may cause Safari to unexpectedly quit or have performance issues