Internal drag-reduction coating in gas line pipes can reduce the eddy current area and turbulence degree so as to improve transportation efficiency and reduce energy consumption and operation cost of compressor stations. At present, domestic internal coatings are mostly solvent-based coatings, which contain a lot of volatile organic solvents (VOC), so they not only do harm to personal health, but may pollute the natural environment. The solvent-free coatings contain no VOC, and they are superior to solvent-based coatings in terms of mechanical properties and chemical medium resistance. In order to overcome the shortcomings of solvent-free epoxy, e.g. high brittleness, poor bending resistance, high viscosity and high construction difficulty, this paper studied coating modification and spraying technological parameter improvement and carried out verification tests in the test section of the China–Russian Eastern Gas Pipeline. And the following research results were obtained. First, solidifying agents have greater influences on the bending resistance of coating. And compared with the solidifying agents of modified and aliphatic polyamine, those of polyamide can significantly enhance the bending resistance of coating. Second, the shorter the side chains of the molecular structure of epoxy resin and the smaller the molecular weight, the lower the viscosity. Third, to prepare coatings, it is suitable to adopt the resin with its viscosity less than 10 Pa·s under the atmospheric temperature as the material and add thinning agent appropriately. Fourth, in the process of coating generation, it is necessary to control the roughness of pipeline inner wall in the range of 30-50 μm, the spraying temperature in the range of 50-70 ℃, the spraying pressure higher than 5 MPa and the coating thickness in the range of 65-160 μm, so as to satisfy the engineering requirements better. Fifth, when the internal drag-reduction coating of solvent-free epoxy is applied in the China-Russian Eastern Gas Pipeline, its energy saving effect is remarkable. In conclusion, the research results solve the construction problem of solvent-free epoxy coating, improve its performance and provide the technical support for the application of the internal drag-reduction coating of solvent-free epoxy.