Save Empire Earth

I havw question , How to make reveal map on custom multiplayer scenario ?

This is integrated in the template you are using, a fix would be by using triggers.

Place a few random units you won't use (such as priests for example.) randomly on the map.

1) Make these priests an object.

2) Make effect: Unit attribute or Class attribute (not sure which one) with Increase LineOfSight and let it increase by 99999%.

3) Make effect: Kill [object=priests]

4) Make trigger:
Looping: Off
Condition: Always True
Effect1: the unit attribute part
Delay: 1 second
Effect2: Kill object.

And if you've placed the priests correctly your map should be fully revealed.

full map or parts?

unfortunately that's the only way. (Atleast, that I'm aware of.)

I could be wrong. I believe when using triggers, the kill command may add +1 to the player's killed units at the end of the game. I would use the remove object effect.