本文讨论了自校法测试数－模转换器（ＤＡＣ）线性误差的两个难点：数学模型的建立和原始数据的测试。对测试仪作了误差分析，导出了估计测量误差的表达式，给出了对比实验结果。自校法测试ＤＡＣ无需对放大器的失调及增益做事先调整，也无需高准确度的标准源及数字电压表，适合于自动测试。 This article discusses the two difficulties of self-calibration testing of digital-to-analog converters (DACs): the establishment of mathematical models and the testing of raw data. The error analysis of the tester was made, the expression of estimation error was deduced, and the experimental results were given. The self-calibration test DAC does not require prior adjustment of the amplifier’s offset and gain, nor does it require a high-accuracy standard source and digital voltmeter, suitable for automatic testing.