A Merseyside Fire and Rescue investigation team believe the fire was lit deliberately and police are conducting an investigation.
There were no injuries, but the salon was described as severely damaged while around eight surrounding flats suffered smoke damage.
A Merseyside Fire and Rescue spokeswoman said: "Residents were standing outside the burning salon. Some of them had heard smoke alarms in the upstairs hallway go off and had then woken their neighbours up to make sure everybody got out of the building.
"Fortunately, no-one was hurt."
Written by Daily Post; Liverpool