Abstract: The best ratio of current to feed-in speed of the standing fluorinated reactor was researched at 90 kA current based on the theoretical calculation. Through calculating theoretically, the superfluous fluorine is 1.04%-3.39% when the standing fluorinated reactor works normally after optimizing the ratio of current to feedin speed. The test results indicate that the 250 kgU/h standing fluorinated reactor works steadily at the ratio of current to feed-in speed of 205-210 A•h/kg. The ratio of current to feedin speed of the standing fluorinated reactor is optimized from 200220 A•h/kg to 205-210 A•h/kg. The utilization efficiency of fluorine increases more than 1% and the unreactive ratio of UF₄ decreases more than 20% after optimizing the ratio of current to feed-in speed.