Oshoala scored in the 43rd minute to put her team 3-1 ahead. She was later replaced on 77 minutes.
She has now netted nine goals in her last seven games in all competitions for Barcelona Ladies this season.
Patricia Guijarro and Lieke Martens were the other scorers for Barcelona Ladies after they got on the score sheet in the 12th and 28th minutes respectively.
While Toni Duggan (4th minute) and Charlyn Corral (62nd minute) scored for Atletico Madrid Ladies.
Barcelona Ladies will now take on Real Sociedad Ladies in the final on Sunday in Salamanca.
In December 2019, it was announced that the Spanish women Super Cup would be created.
The tournament which is a four-team format, include a semi-final round, similar to the new format established for the men’s Super Cup.