The Qataris beat Kazakhstan’s TNC Kazchrome VC in straight sets for their second straight victory.
Skipper John Chigbo and Nadir Abubakr contributed 15 points each for Police in the final against Al Arabi.
Kamil Rychlicki was the star of the show for Rayyan, accounting for 24 points.
The Lions defeated Police in four sets in the final.
Another Qatari side Police finish third.
Rayyan defeated Police in the title clash
Qatar are in Group C, also comprising Australia, Vietnam and Thailand.
The team, coached by Camilo Soto, will start their AVC Cup campaign with a match against Vietnam on August 8.
It was the sixth title of the season for unstoppable Rayyan.
The reigning champions will take on Al Ahli in the final on May 12.
Al Rayyan lead Al Arabi 1-0 in the other best of three semifinals.
The Lions defeated Police to win their fifth title of the season.
Unbeaten Rayyan have an unassailable 46 points with just two rounds to go
Rayyan lead the table with 41 points while reigning champions Police are on 38
The Qatar League leaders eased past hosts Esperance Sportive de Tunis in the final