The invention provides a high-
toughness anticorrosion CrAlN / Cr2AlC multilayer 
coating and a preparation method thereof. The preparation method comprises the steps that a matrix is cleaned and dried, 
etching is conducted on the matrix with 
argon ions, a 
transition layer is deposited on the matrix, the CrAlN / Cr-Al-C multilayer 
film coating is deposited on the surface of the matrix, and low temperature annealing is conducted to obtain CrAlN / Cr2AlC. The 
transition layer is arranged between the matrix and the CrAlN / Cr2AlC multilayer 
coating, and according to the multilayer 
coating, CrAlN hard filmsand Cr2AlC MAX phase films are alternately stacked to form periodic arrangement. The multilayer 
film coating has high 
hardness, low 
internal stress and the high anticorrosion characteristic, and abrasion resistant and anticorrosion lives of the matrix can be prolonged. The problems that a single CrAlN coating is high in 
hardness but insufficient in 
toughness, and a single Cr2AlC coating is good in 
toughness and 
corrosion resistance but low in 
hardness are solved. According to the provided preparation method of the multilayer 
film coating, the multilayer film coating is obtained through the combination of periodic control over the flow of N2 and CH4 reaction gases, with subsequent low temperature heat treatment, the process is simple and easy to control, industrialized production can be achieved, and the prepared multilayer film coating is stable in performance and is suitable for abrasion-resistant anticorrosion protection of tool molds or other 
moving parts in different environments.