The lubricating oil system of compressor is an important part of the auxiliary system of centrifugal compressor, and the oil flushing quality of lubricating oil pipeline in the early stage of operation directly affects the long-term operation of the compressor. How to reduce the time of qualified oil flushing under the premise of ensuring oil flushing quality is the target in the early stage of project construction. This paper analyzes the problems in the oil flushing of oil pipeline of cracking gas compressor unit, puts forward some countermeasures, and presents some methods for improving the oil flushing efficiency, so as to reduce the oil flushing time.