The woman, from the Stroud area of Gloucestershire, forged doctors' notes and made it look as though her son was taking medication for cancer.
She forced him to wear a bandana and sent him to school in a wheelchair, where he was unable to run around and play and became the "butt of jokes".
As well as claiming £85,899.44 in benefits, the woman was given a Vauxhall Zafira to help her transport the boy around.
She sent forged letters to the Department of Work and Pensions and the boy's school claiming he was suffering from autoimmune lymphoproliferative syndrome and lymphoma.
At Gloucester Crown Court, she admitted child cruelty, fraud and forgery and was jailed for three years and nine months.