Stutes boss David Livermore told BBC Radio Cambridgeshire: "He comes from a fantastic football club which has a very good academy.
"I've heard a lot of good things about him, he's a bright young lad, someone they've got high hopes for."
Ainsley made one substitute appearance during a loan spell with fellow Blue Square Bet Premier side Rushden & Diamonds last season and is available for Histon's trip to Luton on Saturday.
Source: BBC Sport
Source: BBC Sport