The third national soil survey has been launched. In order to ensure the accuracy of soil organic matter determination，it is necessary to improve the efficiency of soil organic matter determination and reduce the technical difficulty of soil organic matter determination. The oven heating method under the same test time and different test temperature determined by different scholars was used to measure soil organic matter，and the difference between the method and the oil bath method was analyzed. The results showed that the 150 ℃ constant temperature condition had the better precision， accuracy and reproducibility among the three constant temperature heating conditions of 130，150 and 180 ℃ . The difference significance analysis showed that the measured value of soil organic matter at 150 ℃ was not significantly different from that measured by oil bath method. The content of soil organic matter (x) measured by oil bath heating method was significantly positively correlated with the content of soil organic matter (y) measured by oven heating method (150 ℃，30 min). The regression equation was y=1.0106x+0.3418 (r2=0.999> r0.01=0.661). The standard deviation of soil organic matter measured by oil bath method was 0.14 ～ 0.68 g/kg，and the relative standard deviation was 0.45%-6.43%，while the standard deviation of soil organic matter measured by oven heating method was 0.06-0.25 g/kg，and the relative standard deviation was 0.17%-2.25%， indicating that the oven heating method (150 ℃，30 min) is more accurate and reproducible than the oil bath method. Under the condition of 30 min constant temperature and heat preservation，the optimal heat preservation temperature for the oven heating method to determine soil organic matter is 150 ℃，which can replace the oil bath method to determine soil organic matter，and is more accurate，fast，green，efficient and safe.