This standard specifies the use of infrared Spectrophotometric method, spectrophotometry method for the determination of oil in oily wastewater discharged from the offshore oil development industry, including analytical steps, calculation methods and quality control requirements. The method is suitable for the determination of oil in oily wastewater in the People's Republic of China and its waters under its jurisdiction. The standard describes the extraction of oil substances in wastewater through tetrachloroethylene and the use of Infrared spectrophotometer measurement of light absorption values at specific wavenumbers (2930 cm, 2960 cmand 3030 cm), which are proportional to the concentration of the oil. The standard ensures the accuracy and conformity of wastewater oil analysis during offshore oil development.