The invention discloses an Ag-MAX phase nanometer composite plating layer and a deposition method thereof. A copper contact is used as a basal body; an Ag-MAX phase composite material is used as a target; and a pulse laser deposition method is adopted to form a compact and two-phase uniform nanometer composite material of 100 nm-10 microns on the surface of the contact basal body. A MAX phase is used as excellent elastic modulus and hardness of a ceramic material, so that the arc ablation resistance and the welding resistance of an Ag contact can be improved; and the excellent self-lubricating performance facilitates prolonging the service life of the contact. The method can control the plating layer thickness through controlling the laser pulse number, and controls the plating layer components through controlling the target components to obtain the composite material plating layer with different ratios. Experiments represent that the method can obtain an Ag base composite material with a nanocrystalline structure and uniform two-phase distribution; when the electric conductivity is guaranteed, the hardness, the wear resistance and the ablation resistance are effectively improved; the service life can be prolonged; and the application and popularization values are higher.