Edwin Mee, 45, of Tavistock Road, Croydon, allegedly targeted 11 victims aged 15 to 25 when he was a recruitment sergeant in Croydon and Cheam.
He has denied 17 counts of sexual assault, three rapes and one count of assault by penetration, alleged to have occurred between 2010 and 2011.
Sgt Mee's trial is expected to begin at Southwark Crown Court on Wednesday.
An Army sergeant has denied committing a string of sexual offences against female recruits on military bases.