Gayle, who turned 21 last week, spent five months with the Shrews last season, making 18 appearances and scoring one goal.
He has made one first-team appearance for the Baggies so far as a 70th-minute substitute in the 3-0 Capital One Cup victory over Newport County at The Hawthorns on August 27.
Albion have no right of recall on Gayle, who is likely to feature for Shrewsbury in Saturday's League One trip to Stevenage.
Gayle moves to Greenhous Meadow with the Shrews in 18th spot in League One, three points above the drop zone after 18 games.
Shrewsbury have also re-signed striker Tom Eaves on loan from Bolton Wanderers until January 5.
Eaves, 21, scored six goals in 10 appearances for the Shrews last season during his stay between February 21 and April 15.
He has only just returned to Bolton following a loan spell with Rotherham.
Meanwhile, Shrewsbury defender Connor Goldson has joined League Two club Cheltenham Town on loan.