The content of soil organic matter is an important indicator of soilfertility，and accurate measurement of its content has practical significance for agricultural production and soil environmental monitoring. There are currently two main methods for determining soil organic mattercontent:oneis the potassium dichromate volumetricmethod，the other is the use of high-frequency infrared carbon and sulfur analyzer for measurement. Both methods indirectly determine the content of organic matter in soil by measuring the content of organic carbon and multiplying it by a correction coefficient. This article selected six soil and sediment reference materials with different contents and conducted measurements using two methods to examine the accuracy and precision of these methods. When the organic matter content of the sample waslow，the precision of both methods waspoor，but the potassium dichromate volumetric method was more stable and accurate. As the organic matter contentincreased，the results of both methods showed a stable state. Incomparison，the high -frequency infrared carbon sulfur analyzer method had simple pre-treatmentand convenientdetermination，and was suitable for rapid determination of organic matter in large quantities of soil samples. Selecting soil samples from a certain area in northern Henan for validationexperiments，the organic matter content was determined using potassium dichromate volumetric method and high-frequency infrared carbon sulfur analyzermethod，ranging from 15.8 to 29.0 g/kg. The results obtained by the two methods were basicallyconsistent，with relative deviations of 0.8-1.1 g/kg and 0.6-1.0g/kg，and precision of 2.8%-6.1% and2.1%-6.2%， which met the detection requirements of relevant standards.