Diffusion-weighted imaging (DWI) produces contrast in MRI images through the diffusion of water molecules. Middle ear cholesteatoma is a keratotic squamous epithelial dysplasia, which shows specific hypersignal on DWI. A number of studies have supported the clinical application of DWI as an auxiliary examination method for middle ear cholesteatoma. It is considered that it has high accuracy for both primary and recurrent middle ear cholesteatoma. It can even replace the secondary exploratory operation after middle ear cholesteatoma to a certain extent. This paper reviews the progress of diffusion sequence in the diagnosis of middle ear cholesteatoma, as well as the quantitative analysis and sequence fusion of diffusion technique in recent years.