In this paper, the force controlling bubble formation is calculated in anode reaction region by establishing a two-phase dynamic model. The whole dynamic process of bubble generation, growth, merging and detachment in porous media and microchannels are analyzed in depth. The effects of methanol concentration and discharge current on the bubble in the pores of the diffusion layer are analyzed, and the cross-section effect and hydrophobic effect of the flow channel are simulated. Besides, through visual experiments, a further understanding of cell performance, anode bubble growth characteristics and the behavior of bubbles are established to verify the simulation. Simulation and experimental results both show that the size and number of anode CO2 bubbles are highly correlated with cell operating conditions. More and smaller bubbles are easily generated when the anode reaction is more intense.