More details would help - which watch is it? How long have you been using it? Apps and features that you have enabled...etc.
Thanks for the info. Is it a new watch? If so, then the battery could still be learning your usage and should stabilize in a few days.
Things that consume the battery most are -
1. Hey Google enabled in Google Assistant settings. Disable it.
2. Continuous HR and Stress monitoring. You can change these to 10 mins and manual respectively.
3. Turn off WiFi and NFC if you don't need them.
4. Always on display
In the Wearable app on tour phone, Check in Settings > Battery, which apps, if any are consuming the battery the most. Based on your usage, it should easily last you a full day.
You are welcome!