This paper summarizes the advantages and disadvantages of the Earth system model (ESM) and integrated assessment model (IAM) in investigating the human activities and climate change, and then clarifies the necessity of bidirectional coupling of these two kinds of models. The main difficulties in the bidirectional coupling process are objectively analyzed, and the methods and latest development in solving the coupling difficulties are also summarized at the international and domestic levels, and the uncertainty of bidirectional coupling and the method to solve the uncertainty are discussed in the last part. This paper provides a new guidance for the bidirectional coupling between the ESM and IAM in China.