You have asked an interesting question, but it isn't exactly clear. Whilst there are certainly many references to the life of Charlotte Bronte in the novel, it is clear that, whilst Bronte echoes some of her experiences and uses Jane Eyre as a mouthpiece for her own frustrations as a women in Victorian English society, it is certainly not a direct autobiography of her life.
You might find it interesting to read Mrs. Gaskell's autobiography of Jane Eyre, which is highly insightful and allows the discerning reader to see how some events in the novel are based on Charlotte Bronte's own life. Lowood School, for example is pretty much a direct copy of the school that Jane and her sisters were sent to, and where her two eldest sisters died because of bad conditions. Likewise, the character of Helen Burns is based on Bronte's eldest sister, Elizabeth, who died.
Likewise certain key quotes clearly suggest that Jane Eyre is a figure used by Bronte to express her own desires and struggles, such as the famous "stiller doom" passage where Jane Eyre talks of her own desire for "action" and rages against the position that society has fashioned for women.
However, on reason for being aware of the limitations of reading this text as a biography comes from the text itself. At the beginning of Chapter 10, just as the Lowood episode comes to an end, Jane Eyre herself points to the dangers of treating this as a biography:
Hitherto I have recored in detail the events of my insignificant existence: to the frist ten years of my life, I have given almost as many chapters. But this is not to be a regular autobiograpy: I am only bound to invoke memory where I know her responses will possess some degree of interest; therefore I now pass a space of eight years almost in silence: a few lines only are necessary to keep up the links of connection.
Above all, this excerpt reminds us that we read a carefully chosen selection of events that are selected by the author for a deliberate purpose. The structure of the novel, with its easily identifiable 5 stage breakdown of Gateshead, Lowood, Thornfield, Moor House and Ferndean also point towards artifice - much to neat to be representative of a "real life" biography.
So whilst reading the text as a biography has its uses, overwhelmingly it is a work of literature, that does indeed use and develop incidents from the novelists own life, but is a work of fiction, with an arguably fairy tale ending where a woman is able to get everything she wants in a society where almost everything is set against her.