The present invention relates to a process for obtaining fuel from biomass which comprises the introduction of the catalyst (3) in the base of an cracking section (4), wherein said catalyst (3) at high temperature comes in contact with a gas stream of light hydrocarbons rich in hydrogen (1), wherein the catalyst (3) and hydrocarbon (1) then come in contact with a lignocellulosic liquid stream (2) in the same cracking section (4), creating the reaction mixture (5) that, soon after, comes into contact with the main stream containing the traditional fossil load of a FCC (6) in a second cracking section (7).