use siri without unlocking my watch

Hi

No - if your Apple Watch is locked, then it is not possible to use Siri.

If you are not yet doing so, then you might wish to use these settings:

• On your iPhone, in the Watch app, go to: My Watch (tab) > Passcode:
• Turn Wrist Detection on.
• Turn Passcode on.
• Enable Unlock with iPhone.

After putting it on your wrist, your Apple Watch will then unlock after whatever you do first: either unlocking your watch manually (by entering the passcode) or unlocking your iPhone. It will then remain unlocked (including when the screen is asleep) until you remove it from your wrist. When you remove your watch, it will lock automatically:

Turn on, wake, and unlock

With your Apple Watch unlocked:

• If you wish to use the "Hey Siri" command, then first also wake the display, either by raising your wrist or by tapping the screen before saying "Hey Siri".
• Or press and hold the Digital Crown to activate Siri.

More information:

Use Siri on your Apple Watch - Apple Support

Yes, wake the watch by lifting your arm, state "Hey Siri . . ." and whatever command you'd like.