does conquer empty battlefield count as win combat?

No. Conquering an empty battlefield is not considered winning a combat — no Combat occurred.

Combat only happens when opposing players have units at the same battlefield (Rule 438/461). Moving to an empty battlefield creates a Non-Combat Showdown, which closes without a combat result (Rule 348.2). You still establish control and Conquer (scoring the point), but because there was no Combat Showdown, there's no attacker/defender, no combat winner, and no Combat Cleanup (units don't heal). (FAQ #9092)