How can I prevent Siri from launching when my iPhone is locked? How do I stop Hey Siri from answering on the iOS lock screen?
You can disable the ability to access to Siri from your lock screen by navigating to Settings >> Siri & Search. Tap the Allow Siri When Locked On/Off slider, under the Ask Siri section, to turn it off. This will stop anyone from accessing Siri while your phone is locked.