The development of nanomaterials is crucial to upgrading of modern industry. MXene nanosheets have attracted significant attention due to their superb resistance to permeation, diverse surface chemical properties, impressive mechanical properties, and metal-like electrical and thermal conductivity, etc., providing unique advantages in various technical fields. When MXene nanosheets are combined with polymers to form functional coatings, their applications span multiple fields, including anticorrosion, wear resistance, flame-retardancy, electromagnetic interference (EMI) shielding, and de-icing. This review, in conjunction with MXene's barrier property, lubricity, thermal stability, conductivity, and photothermal conversion property, discusses in detail the various applications of MXene-based polymer coatings. Additionally, it examines the dispersion and interaction of MXene within polymer coatings and the role of functionalized MXene in polymers. Finally, based on the current research status and emerging needs, the development challenges and future research opportunities of MXene-based polymer coatings in a targeted manner are discussed. This review aims to summarize the existing research results and put forward an objective and fair point of view, providing a constructive reference for upgrading modern nanofunctional polymer coatings.