The invention relates to an integral treatment process of the oily sewage of an oil field. The process flow in the invention is as follows: settling sand, removing oil, breaking emulsion through air flotation, treating with a microwave-enhanced Fenton system, performing flocculation and air flotation, performing precision filtering, performing catalytic ozonation with an activated carbon fiber felt, and performing ultrafiltration to obtain clean water. By adopting the integral treatment process, the operations of oil removal, emulsion breaking, advanced oxidation, flocculation, catalytic ozonation and membrane separation can be continuously realized. The floor space of equipment in the invention is small; the treatment process is suitable for various oily sewage and has obvious treatment effect; the removal rate of the chemical oxygen demand (COD) of raw water is more than 96%, and the oil content and the removal rate of suspended matters are 100%; and the turbidity of the obtained water is 4-6 NTU. The main indexes of the process provided by the invention such as the COD, oil content, suspended matters, turbidity and the like are better than those of the current oily sewage treatment process in oily sewage treatment; and the quality of the treated water can meet the related rules of the Integrated Wastewater Discharge Standard (GB8978-1996) and the Environmental Quality Standards for Surface Water (GB3838-2002).