Surface processing technology can be traced back to the ancient, and later formed three industries of paint, electroplating, and thermal spraying. In 1960s, the electron beam, ion beam and laser beam entered the surface processing technology field, which caused the change and progress of surface technology, and gradually formed the modern surface engineering. The paper discusses the exact definition of modern surface engineering, two principles of use, three major technologies, four major functions, and the formation of surface engineering. The theory, technology, materials, processes and standards for the application of the protective layer on the surface of an object are called surface engineering. Two principles are the principle of simultaneous design and manufacture of the surface and the overall, and the principle of establishment and maintenance of the integrity of surface protection. Three major technologies include surface modification and conversion technology, thin film technology and coating technology. Four features include control of corrosion, friction and lubrication, surface functional transformation and surface decoration. Surface engineering includes a solid theoretical foundation, strong technical content, the design of the surface protection layer, the implementation of the engineering workshop design and testing, and a wide range of applications in different fields.