为使钢材脱碳层深度测量更加准确和可靠，对比分析了ISO 3887：2017规定的平均法与GB/T 224—2008规定的五点平均值法。采用两种方法分别测量了60Si2CrVAT钢线材的脱碳层深度，并对测量结果采用综合评定法进行测量不确定度评定。结果表明：五点平均值法测量结果的扩展不确定度较平均法的小。五点平均值法得到的平均值波动较平均法的小，检测结果的复现性较平均法的更好，出现检验问题时更适合进行验证。

In order to make the measurement of the depth of decarburization layer more accurate and reliable, the average method in ISO 3887:2017 and the five point average method in GB/T 224—2008 were compared and analyzed. The decarburization depth of 60Si2CrVAT steel wire rod was measured by two methods, and the measurement uncertainty was evaluated by the comprehensive evaluation method. The results show that the expanded uncertainty of five point average method was smaller than that of average method. The fluctuation of average value of five-point average method was smaller than that of average method, and the reproducibility of detection results was better than that of average method, which was more suitable for verification in case of test problems.