In this paper, a multicomponent multiphase pseudopotential Lattice Boltzmann method with Multi Relaxation Time (MRT) collision operator is presented to study the dynamic behavior of liquid droplets movement and coalescence process in the gas channel of PEMFC. In the numerical method, the forcing term is improved in order to achieve the high density ratio and thermodynamic consistency. First, the density ratio, Laplace law, and contact angle are validated. Different parameters, such as pressure difference, surface contact angle, radius of droplets, and distance between two droplets during the movement of droplets and the coalescence process, are studied. The simulation results show that increasing the pressure difference between the two sides of the channel increases the flow velocity as a result of increasing the shear force and eventually faster movement of the droplet in the gas channel. Simulation performed for the effect of contact angle shows that a hydrophilic surface creates a resistance force between the droplet and the wall and reduces the amount of shear force. Hence, the velocity of the droplet in the channel decreases while the hydrophobic surface acts in the opposite direction. Also, droplet coalescence is useful for droplet movement because the velocity between the droplet and the top of the wall increases, and the shear force applied to the droplet increases during cohesion.