Molecular dynamics(MD) simulations are performed to investigate the wettability of liquid metal on the metal substrate. Results show that there exists different wettability on the different metal substrates, which is mainly determined by the interaction between the liquid and the substrate. The liquid metal is more likely to wet the same kind of metal substrate,which attracts the liquid metal to one side on the hybrid substrate. Exchanging the liquid metal and substrate metal has no effect on the wettability between these two metals. Moreover, the study of metal drop coalescing indicates that the metal substrate can significantly affect the coalescence behavior, in which the changeable wettability of liquid metal plays a predominant role. These studies demonstrate that the wetting behavior of liquid metal can be controlled by choosing the suitable metal substrate. Molecular dynamics (MD) simulations are performed to investigate the wettability of liquid metal on the metal substrate. Results show that there exists different wettability on the metal substrate. Which is mainly determined by the interaction between the liquid and the substrate. is more likely to wet the same kind of metal substrate, which attracts the liquid metal to one side on the hybrid substrate. Exchanging the liquid metal and substrate metal has no effect on the wettability between these two metals. coalescing that that the metal substrate can significantly affect the coalescence behavior, in which the changeable wettability of liquid metal plays a predominant role. These studies demonstrate that the wetting behavior of liquid metal can be controlled by choosing the suitable metal substrate.