In the process of deep reduction and low intensity magnetic separation of rare earth tailings with an iron grade of 13.06％, fixing fluorine agents such as CaO was used to reduce under the condition of high temperature emission ratio of fluor in rare earth tailings.The effects of processing parameters,such as the type and dosage of fixing fluorine agent, the temperature and time of roasting on the iron grade, the recovery of the RE and the fluorine content in rare earth were studied.And means of SEM, XRD were used to analyze the rare earth tailings and the roasted products.The following results were found through the study that magnetic iron powder with Fe grade of 60.18％ and the RE recovery ot91.23％ was obtained under the condition of the roasting temperature of 1200C, roasting time of 120 min and grinding fineness of-74μm.In the calcinations process of the rare earth concentrate, the fixed fluorine content of rare earth tailing in a certain range varied linearly with the increase of fixing fluorine agent-CaO.Meanwhile, the main product is CaF2 ,which was helpful for enrichment and recovery of fluorite.