Cesm is a new generation of earth system model released by the National Atmospheric center of the United States in 2010. It is one of the most advanced and widely used earth system models. Cesm uses couplers to simulate the climate in collaboration with the atmospheric, oceanic, land surface, sea ice and other component models. It is composed of five component models: atmosphere (ATM), ocean (OCN), land surface (LND), sea ice (ice) and land ice (GLC) and a coupler (CPL) that controls the interaction of each component. Each component model can be selected from dynamic model and data version model, which can be combined to meet different research purposes Couplers are both parallel models. They support both distributed memory and shared memory parallel mechanisms, and can use various computing resources flexibly.