Abstract: Provided in the present disclosure is a liquid metal substrate cleaning method and cleaning and coating integrated device, belonging to the technical field of thermal interface materials construction. The above-mentioned method includes a substrate cleaning and a cleaning qualification inspection, wherein the substrate cleaning comprises a plasma cleaning, an inorganic cleaning reagent cleaning, and an organic reagent cleaning, and any combination of the plasma cleaning, the inorganic cleaning reagent cleaning and the organic reagent cleaning; and the cleaning qualification inspection is judged as qualified or not based on a diffusion area of the organic reagent on a surface of the liquid metal substrate, and when the diffusion area meets a predetermined requirement, the cleaning is finished; and when the diffusion area does not meet the predetermined requirement, the substrate cleaning step is repeated, and the steps are repeated in this way until the diffusion area meets the predetermined requirement.