•Summarized the experiment of desalination by graphene-based nanomaterials.•Focus on computer simulation on the desalination by graphene-based nanomaterials.•The gap between the results of experiment and simulation were discussed in detail. Reverse Osmosis (RO) for the desalination of saline water is associated with tremendous energy costs and low efficiency. Biomimetic membranes incorporate biological elements or borrow concepts, ideas or inspiration from biological systems. Such membranes can take advantage of the strategies evolved by nature over billions of years for improving transport efficiency and specificity. Biomimetic membrane based on graphene has achieved great progress on the desalination performance. With the development of nanotechnology and computational science, the computational simulation has been a powerful tool to uncover the atomic details in desalination by graphene based biomimetic nanomaterials. In this mini review, we will summarize the experiment of desalination by graphene-based nanomaterials and focus on computational simulation on the desalination by graphene-based nanomaterials. Especially, the gap between the results of experiment and simulation will be discussed in detail.