Abstract: In recent years，various industries have higher requirements on the service performance of steel materials，so continuously improving the cleanliness of steel and reasonably controlling inclusions in steel have become important tasks for various steel enterprises，and the excessive oxide inclusions in steel are related to the deoxidization process. In this paper，through industrial test，X-ray fluorescence analyzer and scanning electron microscope (SEM)，the effect of deoxidation methods on the total oxygen content，inclusion evolution and slag oxidizability of No.70 steel has been systematically studied. The experimental results showed that different deoxidization methods had little effect on the types and sizes of inclusions in No.70 steel. The deoxidation method of adding 1.2kg/t Si-Ca compound deoxidizer in two stages and three batches per stage was to the benefit of reducing slag oxidizability and further removal of oxygen content in steel，so as to control the slab of No.70 steel with lower total oxygen content and amount of oxide inclusions. Using this deoxidation method，the total oxygen content could be controlled between 0.001 3% and 0.001 5%，and number of oxide inclusions could be controlled between 10.2--11.3/mm2. The results of this study can provide theoretical basis and technical guidance for the high-purity control of high carbon steel used for high quality rope grade fine steel wire.

Key words: deoxidation method, No.70 steel, total oxygen content, slag oxidizability, inclusion