Northern peatlands are significant carbon reservoirs, serving as long-term atmospheric carbon dioxide sinks and sources of methane. However, methane processes interacting with environmental changes in Northern peatlands, remain unclear. Therefore, the need for better simulation of key processes of methane in peatlands is still urgent. In this study we developed the hourly process-based CoupModel for modeling the methane fluxes in the peatlands, with detailed considerations of the gas transport and vegetation. We applied the new CoupModel-CH4 to three peatland sites (Degero, Stordalen, and Zackenberg) along the Boreal-Arctic climate gradients, with soil status from seasonally frozen, to thawing permafrost and permafrost. We will depict the model performance at hourly, daily and monthly scales from three sites, and compare the responses of three peatlands to recent climate change and the controlling mechanisms for CH4 emissions. Our study will provide new insights into the emission mechanisms of methane in Boreal-Arctic peatlands and contribute to a better understanding of northern peatlands for both modelling and observation communities.