To accurately understand the insulation status of primary heating pipe network in the Chengyin District of Daqing City, its present insulation status has been tested through the enthalpy drop method. The field test results, with the data processing, are compared and analyzed, which reveals that there are weak links in the insulation structure of the primary heating pipe network in the Chengyin area. Before the insulation structure is optimized according to the field conditions, which provides a basis and reference for testing the insulation status of the heating pipe network, and has a guiding significance for evaluating and optimizing the insulation structure of pipe network.