Canon Gordon Rideout, 74, abused more than a dozen girls and boys at the now-closed home at Ifield Hall in Crawley, West Sussex, over a four-year period.
The former Anglican clergyman also indecently assaulted two girls at an Army site in Middle Wallop, Hampshire, said the Crown Prosecution Service (CPS).
At Lewes Crown Court, Rideout was found guilty of 34 counts of indecent assault and two counts of attempted rape on 16 children between January 1962 and January 1973. He was cleared of one count of indecent assault on a boy at a second Barnardo's home in Essex.
Most of the charges Rideout was convicted of related to his time as an assistant curate at St Mary's Church in Crawley when he would visit a Barnardo's children's home in the county.
Prosecutor Philip Bennetts QC told the jury that Rideout would visit the home and "it would appear from the evidence that he would wander the house and indeed the grounds unaccompanied, and he would visit children when they were sick and alone in bed".
One of his victims recalled Rideout visited the dormitories at night, put his hands under the covers and would "fondle around". Mr Bennetts said: "It was on a regular basis when he came to stay, maybe once, twice, three times a week sometimes."
Jurors heard how Rideout attempted to rape a girl who attended choir practice. After one occasion in his flat, they heard that Rideout walked the girl back to the children's home and told her: "This is going to be our secret."
A month after another rape attempt in a wooded area, the court heard, the girl believed she was pregnant.
When she confided the abuse to a friend who went on to tell a manager at the home, the victim was allegedly slapped across her face.
At the home, Mr Bennetts said there existed a "brutal regime where children were taught how to behave by beatings".
One girl, who was aged around 14 or 15 at
the time she was abused, was asked why she had not reported it to the
authorities sooner.
She told police in interview: "I was too scared, too
scared. I didn't want to be beaten again, too scared. The beatings were
so much worse than what that man was doing. The beatings were terrible,
absolutely terrible."
Rideout, of Filching Close,
Polegate, East Sussex, was arrested in March last year and charged five
months later following a nine-month inquiry by Sussex Police.
He denied
all the charges and will be sentenced later.