通过对多晶硅各生产工艺过程中碳元素来源、分离提纯、转化分布等情况进行分析，找出控制硅粉中碳质量分数，优化提纯工艺参数等措施来控制氯硅烷中碳质量分数从而控制产品多晶硅中的碳质量分数，同时严格控制氢气中甲烷质量分数也可以降低产品中碳质量分数、提升产品质量。

Carbon elements in polysilicon products are studied over the whole polysilicon production process.It is found through analysis on carbon source,separation and purification and transformation that the carbon content in trichlorosilane can be controlled by controlling the carbon content in silicon powder and optimizing the purification process parameters.Carbon content in polysilicon product can be reduced and the polysilicon product quality can be improved through controlling strictly methane content in hydrogen.