Abstract: In order to play the role of refining high quality steel and process rhythm adjustment ability of ladle furnace, the molten steel composition adjustment and optimization in ladle furnace process were researched. The work would help to realize fast and accurate alloy calculation, reduce processing cycle, and improve process rhythm adjustment ability. The work was also in favor of realization of automatic weighing,automatic addition as well as reduction of labor intensity. It would achieve the lower limit control for the molten steel composition and reduce alloy consumption,especially,for the precious alloy. It also would realize narrow composition control for molten steel,improve the quality of steel and achieve a material to be multi-purpose,etc. In order to establish the model of molten steel composition adjustment in ladle furnace,the derivation process and analysis of alloy calculation formulas were given for the first time. The flow diagram for the ladle furnace molten steel alloy composition fine-tuning was given. And a foundation for the ladle furnace process optimization had been lain.