Abstract: In order to obtain a relatively stable temperature field, the changes in the temperature field of the methane-oxygen premixed flame at different ratios were obtained through experiments, and the influence of the methane mass fraction on the temperature field of the premixed flame was analyzed. With the help of Mckenna burner, digital holographic technology was used to obtain the interference fringe images of the premixed flame temperature field under different methane-oxygen ratios, and the Butterworth low-pass filter was used to reduce the speckle noise of the pre-processed image. The phase distribution information of the temperature field was extracted by the improved four-way least squares unwrapping method. According to the theoretical relationship between the phase and the temperature, the corresponding temperature information data was obtained, and the B-type thermocouple was used for experimental verification. The experimental results show that the temperature measured by this method is basically consistent with the temperature change measured by the thermocouple under the same conditions, which proves the feasibility of the digital holographic technology to measure the temperature field. When the mass fraction ratio of methane to oxygen is 0.9, the temperature change is about 10K. And the temperature field distribution is the most stable one compared with other working conditions. This research provides a theoretical basis for the related research on methane-oxygen premixed gas and the application of Mckenna burners.