The report into Steiner Academy Bristol was published last week and found a raft of concerns including staff using "inappropriate physical intervention" in dealing with children.
The concerns are so serious that the school has been placed in special measures.
Inspectors also found frequent incidents of bullying and that teachers have low expectations of pupils' achievements. The leadership and governers are also criticised for failing to effectively tackle problems at the school.
But in a statement issued this week the governing body has said it plans to launch a legal challenge into the inspection, which took place last November.
They say that the inspection followed a letter sent by Education Secretary Damian Hinds to Ofsted calling for additional scrutiny of Steiner schools. The Bristol school's government body says this may have influenced the "fairness and independence" of the inspection process.
"While we take the report very seriously and recognise that improvements need to be made, we do not consider that the decision to place us in special measures was fair," said Ray Douglas, a governor at Steiner Academy Bristol.
"We have a number of concerns about the way the inspection process was conducted and the judgments made and wanted to work with Ofsted to resolve these.
"Unfortunately we feel that the position Ofsted has adopted throughout this process has left the board of governors with no other option to pursue a legal challenge.
"We are concerned about Ofsted's approach and what this means for the future of state-funded Steiner education."
The school's governing body has instructed lawyers and launched a crowdfunding appeal for its legal challenge. It also says it has collected a 1,000 strong petition from parents calling for a fresh Ofsted inspection.
Steiner Academy Bristol is one of four state funded Steiner schools set up under the government's free school programme.
Steiner education is based on the teachings of Austrian academic Rudolf Steiner, who died in 1925. Steiner schools have a broad curriculum that emphasises emotional, physical and spiritual learning alongside academic, and is structured around the different phases of child development.