A numerical model was constructed by Fluent software in this study with the objective to evaluate the model performance of predicting impinging flame heat transfer. The mechanism of methane-air-2step provided by the software and a Chemkin-compatible mechanism are used. With other conditions unchanged, the flame and heat transfer characteristics of the flame were computed and compared. Both mechanisms over predicted the height and maximum temperature of the flame by referring to the experimental data. The highest temperatures were found in small hot spots which are found to influence the impingement heat transfer at large nozzle-plate distance. Overall, the Chemkin mechanism gives a more reasonable temperature field and better predicts flame height and flame structure due to the more species and reactions considered. Both mechanisms can follow the experimental heat flux variation. The Chemkin mechanism better predicts heat transfer quantitatively, while the Fluent mechanism may be preferred by engineers for a qualitative analysis with lower computational cost.