本文报道了用高频红外碳硫仪测定碳化硅纯度的新方法。试样在瓷坩埚中灼烧，去除游离碳及挥发份，选铁屑与钨粒的混合物作助熔剂，在高频红外碳硫仪上测定ＳｉＣ中碳的含量，由此换算出ＳｉＣ的含量。方法简单、快速、准确。 This paper reports a new method for the determination of silicon carbide purity by high frequency infrared carbon and sulfur analyzer. The sample is burned in a porcelain crucible to remove free carbon and volatiles and a mixture of iron filings and tungsten particles is used as a flux to measure the carbon content in the SiC on a high frequency infrared carbon and sulfur analyzer so as to convert the content of SiC . The method is simple, fast and accurate.