IR降作为管道阴极保护电位测量中不可消除的误差，会影响所测管道阴极保护电位的大小，从而影响管道阴极保护有效性的判断。采用正交试验方法研究各影响因素与管道IR降之间的关系，通过试验数据的处理，得出管道IR降与各影响因素之间的数学模型，并分析影响管道IR降的主导影响因子。结果表明：管道IR降的主导影响因素是防腐蚀层破损点面积、破损点位置及外加电压；IR降与各因素之间符合多元非线性回归。

IR drop, as an error which cannot be eliminated in the measurement of pipeline cathodic protection potential, affects the measured value of pipeline cathodic protection potential, leading to influence the judgment about the effectiveness of pipeline cathodic protection. The relationships between IR drop and its influential factors were studied by means of orthogonal experiment method. Mathematical models between IR drop and its influential factors were achieved by experimental data process. And the dominant factors affecting pipeline IR drop were analyzed. The results show that the damaged area and location of anticorrosion coating and the impressed voltage were the dominant factors which affected pipeline IR drop. The relationships between IR drop and influential factors followed nonlinear regression.