Abstract: In order to find a way to use manganese ore in converter directly and improve the recovery ratio of manganese in the ore, the thermodynamic parameters of manganese ore melting reduction process were discussed to improve the recovery ratio of manganese , and the industrial test was carried out. The results showed that the efficient and stable ‘tri-de’(dephosphorization/desulphurization/desiliconization) pretreatment of hot iron was the basic premise for the success of manganese ore smelting reduction technology. According to the theoretical calculation, when the content of MnO in slag is 5~10% and the terminal content of [C] is 0.13~0.36%, the terminal content of [Mn] in molten steel can be controlled above 0.3%. Under the existing slag amount and other technological conditions, when the amount of manganese ore added was under 10 kg·t-1, the industrial test results showed that the manganese recovery ratio of manganese ore was more than 40%, and the average recovery ratio was 51.40%. In order to get a perfect recovery ratio of manganese, it is suggested to control the total amount of manganese smelting reduction slag from 40 kg·t-1 to 60 kg·t-1 strictly, and the amount of lime is 10~15 kg·t-1. this research results would provide important reference for the development and application of manganese ore used in converter directly.