Gasification kinetic parameters are valuable for designing a gasifier and optimizing operation conditions. In this work, a novel kinetic model named the apparent kinetic model (AKM) is presented and used for kinetic modeling of petcoke gasification under CO2 or steam atmospheres at high temperatures. The AKM was obtained from the Boltzmann equation distribution, which was consistent with the simplified gasification mechanism of petcoke at high temperature. The AKM was used for modeling petcoke gasification at various conditions to verify the applicability of the model. The kinetic modeling results of AKM and three common models were also compared in detail. The fitting results showed that the AKM prediction agrees very well with the gasification experimental results under two atmospheres at high temperature. It was amazing to find that the fitting values, such as t(0.5), were close to the experimental values, with a very limited deviation. The fitting-corresponding R-2 values of AKM were above 0.99 for most conditions, which indicated that AKM was suitable for petcoke gasification at high temperature with high accuracy. It was found that the gasification profile can be described well by AKM, whereas the other three common models showed great deviations in both low and high carbon conversion ranges. It can be concluded that the results of AKM are the best when used to simulate petcoke gasification at high temperature. The kinetic parameters obtained by AKM were accurate and conformed with the gasification reactivity of petcoke, which indicated that the AKM was an appropriate kinetic model for modeling the gasification of petcoke at high temperature.