If I stay in Hong Kong short visit, I want visit Macau for a day Is it worth it ?

If you go there just for one day, you can go to the Historic Centre of Macao, Ruins of St. Paul’s, The Museum of Macao, Camoes Garden and Grotto, Senado Square and other places.

Ferries between HK-Macao Ferry Terminal and Maritime Ferry Terminal are in service for 24 hours, so you can surely take a round-trip from/to HK.