Abstract: In order to explore the electrothermal properties of tubular film samples, a special device for electrothermal performance test experimental system is designed. The system through the external circuit module to achieve sample surface temperature control, the use of multiple temperature recorder to obtain the sample temperature change law with time, and infrared thermal imager to take the temperature change image of the film. The mechanical structure is designed to achieve electrothermal performance testing of samples with an outer diameter φ 3-50 mm and a length of L 10-400 mm, and the electrothermal properties of SnO₂:F tubular film samples with φ 7 mm×L 49 mm at input voltage changes of 14-21 V are tested experimentally. The performance change of tubular film sample aging and electrothermal cycling test can be evaluated, and the results show that the resistance change rate of SnO₂:F tubular thin film samples is about 11.6%, and the thermal efficiency is about 0.859×10^-4W/(℃·mm²) during the electrothermal test.