Ainsworth, who can play up front and on the right of midfield, is a product of the Derby youth system and has had spells on loan at Halifax Town and Bournemouth this season.
The youngster will be in the squad for this weekend's match against Mansfield Town but after the 4-0 thrashing of Bury last week, he may have to wait for his debut.
Ainsworth will be on loan for the rest of the season and therefore will be available to play in the play-offs if Wycombe make it that far.