Abstract: Infrared imaging radiation thermometry has emerged as a robust approach for achieving precise online two-dimensional temperature measurement of gas turbine combustor wall, which is of great significance to ensure operational safety of unit and accurate fault diagnosis of equipment. Regarding the predominant external interference factors in the process of gas turbine combustor wall radiation thermometry, a comprehensive error correction method that took consideration of both gas effect and background reflection interference was proposed. Through rigorous spectral analysis of high-temperature gas radiation characteristics, the wavelength band of 3.7~3.9 μm was selected for measurement, with particular emphasis on the necessity of compensating for gas radiation interference through experiment. Meanwhile, the equivalent background reflection temperature was fitted as a function of squared gas flow rate and air-fuel ratio. Finally, surface temperature measurement of the specimen was conducted on a simulated combustor test rig across various operating conditions. Results show that the proposed error correction method yields an average measurement accuracy of 0.722%, which satisfies practical application requirements.