For example, make Hunter Killer can harvest resource, build structure....

You have to check certain boxes in datedit or whatever unit editor you use, for example "gathers resources".
Also, you must give the Hunter Killer (example) the order set for a worker.

I have checked "resource miner" box in datedit, change AI action, change iscript animation like a worker, make buttons set like a worker but it still don't work. The Hunter Killer look like SCV but it don't harvest, repair and build

Hunch: Requirements? If you didn't edit the requirements for the buildings and stuff that you want the Hunter Killer to make, then it won't make them; iirc Repair and possibly Gather also have reqs that need to be updated. Look under the Requirements tab in Firegraft.

I have change the requirement for the buildings:
Current unit is...
Hunter Killer
Is not constructing
but it still not working