The 22-year-old has completed a medical and will be available for the next match against Leeds United on Saturday 12 September – subject to international clearance.
After spells with Hertha Berlin and Sturm Graz he joined Salzburg in January, scoring six goals in 21 games for the Austrian champions.
Brentford head coach Marinus Dijkhuizen said: “With Andre Gray leaving us, we needed a new striker who was similar in style. And with Marco we have found a very good replacement.
“He is used to playing at a very high level and has experience of international football. He is a good finisher but also has specific qualities that can suit us, like running in behind defenders.
“With Philipp Hofmann also available, I am very happy we have now two quality strikers of differing styles.”
Djuricin has two caps for his country, making his debut in a European qualifier against Liechtenstein in March.