Abstract: This is an essay in the field of metallurgical engineering. Aiming at the problem that the rare earth enrichment after magnetic separation of iron ore tailings in Yen Bai Province, Vietnam cannot be directly utilized, the sulfuric acid roasting process and extraction and enrichment transformation technology are used to carry out experimental development. The process parameters of sulfuric acid roasting, water leaching, impurity removal, transformation and other processes were systematically studied and observed how work on the effect of the experiment and the most optimum technological conditions were determined. The experiment showed the acid and ore ratio (volume: mass) is 0.7, the roasting temperature is 250 degrees Celsius, the roasting time is 2 hours, the leaching water and ore ratio is 4, and the roasting and leaching process was carried out under the above conditions. Impurity removal was carried out with a concentration of 0.1 g/mL and a pH of 4.2 as the endpoint. The grade 5 counter-current extraction was carried out under the O/A of 1.5~2, the 5 counter-current back extraction was carried out under the O/A rate of 10:1, the overall recovery rate reached 90.1%-92.88%, the rare earth concentrations is 1.5 mol/L, the content of iron and aluminum is lower than 100 μg/mL, and met the requirement of the industrial applications, and realized the utilization and development of the accompanied rare earth resources of the iron ore tailings in Yen Bai Province, Vietnam.