Crystalline silicon sawing waste is an important new energy solid waste. However, during the slicing and storage process, the surface of the silicon sawing waste tends to form a high melting point oxide layer, which makes the internal liquid silicon wrapped by the high melting point oxide layer during the high-temperature melting process, further resulting in longer melting time, high energy consumption, low silicon powder yield, and other challenges. Besides, low-quality silicon is recycled by the existing ordinary lime melting method due to phosphorus contamination of the silicon sawing waste from the electroplated diamond wire during the slicing process. Therefore, the silicon recycled from the melting of silicon sawing waste is a potential raw material for silicone production. In this work, silicon for organic use was successfully prepared by removing the surface oxide layer and non-metallic impurities of elemental phosphorus from crystalline silicon cutting scrap in one step using slag refining. Firstly, the high-temperature melting behavior of the oxide layer was simulated using silicon oxide. The effect of two slag systems, CaO-Al2O3-SiO2 and CaO-SiO2-CaF2, on the dissolution ratio of silicon oxide was compared. The influences of refining time (2~6 min) and refining temperature (1400, 1450, and 1500℃) on the dissolution ratio of silicon oxide were also investigated. Then, the effect of two refining slag systems on phosphorus removal was compared by using silicon sawing waste as raw material. The dissolution mechanism of the oxidation layer and phosphorus removal results were analyzed. The results showed that the dissolution of silicon oxide was mainly influenced by the viscosity of the refining slag system. The dissolution rate of silicon oxide can be improved by reducing the viscosity of refining slag. Compared with the CaO-Al2O3-SiO2 slag system, the dissolution rate of silicon oxide was faster in the CaO-SiO2-CaF2 slag system at the same conditions. The refining experiments showed that increasing the basicity of CaO-Al2O3-SiO2 and CaO-SiO2-CaF2 refining slag systems was beneficial to the phosphorus removal of silicon sawing waste. The maximum removal ratio of phosphorus was 53.81% and 62.04% for the two refining slags, respectively.