The method of electric preheating pipelines in the district heating system was introduced. The thermal-structural coupling analysis was used for the electric preheating insulation pipe by ANSYS. The three-dimensional transient finite element model of electric preheating pipeline in the district heating system is established according to the principle of thermology and mechanics. Through the experiment, the result obtained with experiments agrees with the finite element result. And it makes theoretical deduction and experimental analysis to electric preheating method. By analyzing energy, the current of electric preheating has been obtained. Basing on the test data of measuring current of several heating pipelines, these formulas have advantage of easy calculation, wide applications, high reliability and less error rate. (C) 2012 Elsevier B.V. All rights reserved.