Environmental sensitivity areas need more investment to treat and process environmental pollution from waste drilling fluids than non-sensitivity areas because the former was closer to rivers, villages, farmlands, etc., which not only increased the burden of enterprises, but also constrained the sustainable development for oilfields. In order to overcome the challenge of treating waste drilling fluids in environmental sensitivity areas, harmless treatment technology and formulas for waste drilling fluids were developed and determined in this study. The basic formula was: 10.0% SD-4 + 2.5% SD-5 + 9.0% SD-6 + 7.0% SD-7. This technology broke through the traditional curing processing technology and it was successfully applied to two oil wells in Wenmi environmental sensitivity areas. The results showed that the main pollutants were below the requirements of related state environmental protection standard limits and had some porosity and soil-like characteristics. Therefore, the aim of harmless treatment and restoring drilling of waste drilling fluids was realized and the ecological environment of environmental sensitivity areas was well protected.