The open prison, in Warrington, houses 304 young adults aged 18 to 25.
A report by HM Inspectorate of Prisons found it is "safe", with low absconding rates, low incidence of self-harm and any anti-social behaviour addressed.
However, some prisoners criticised officers as "petty" and complained the food was poor.
The report found security levels were appropriate, but some rules were being used unnecessarily, with disciplinary procedures invoked too hastily.
Most prisoners were engaged in learning and many of those go on to earn qualifications.
Inspector Nick Hardwick said more work was needed to promote diversity and integrate foreign national prisoners.
He added: "In three of our four healthy prison assessments, we have awarded our highest marking, and managers and staff should be commended for this.
"This report highlights a small number of important issues requiring improvement and our recommendations will, hopefully, assist in that process."
Michael Spurr, CEO of the National Offender Management Service, said: "I'm pleased that Thorn Cross has been recognised for its continued good work around preparing the young men for their release."
Thorn Cross is "one of the better" prisons, with low levels of violence and high numbers of inmates achieving qualifications, inspectors said.