Abstract: The basic concept and main characteristics of digital factory (digital refinery) were discussed， and the integrated technical architecture was also proposed. Then the key technologies and typical applications of digital refinery were introduced， and it was also pointed out that the transformation-and-upgrading of digital refinery was performed step by step， which was described as from digital refinery via intelligent refinery to smart refinery. This contributed to the construction of smart refinery for process industry.

Key words: digital refinery, digital factory, upgrading of digital refinery