Former Australia batsman Di Venuto, 42, replaced Graham Ford at the Oval in February and helped his side reach the final of the One-Day Cup last season.
Meanwhile, ex-Surrey and England player Vikram Solanki has been appointed as an assistant coach.
The 40-year-old, who retired in 2015, captained Surrey's second team last season as a designated non-batsman.
Former England and Glamorgan coach Rob Ahmun has also joined the club, working as head of strength and conditioning.
"The addition of Vik and Rob further strengthens the quality of our management and coaching staff," director of cricket Alec Stewart said.
Surrey head coach Michael Di Venuto has signed a two-year contract extension to stay with the club until 2019.