The bioaugmentation performance is severely reduced in the treatment of high saline pesticide wastewater because the growth and degradation activity of pesticide degraders are significantly inhibited by high salt concentrations. In this study, an artificial halotolerant degrader J9U-MP capable of mineralizing p-nitrophenol (PNP) substituted organophosphorus pesticides (OPs) [e.g., methyl parathion (MP)] was created by integrating a MP-mineralizing pathway into the genome of a salt-tolerant chassis Halomonas cupida J9. MP degradation coupled with stable isotope analysis indicated that J9U-MP was able to metabolize MP as a sole carbon source to finally produce CO ₂ and H ₂O in high-salt media (up to 120 g/L NaCl). J9U-MP was genetically stable during passage culture and exogenous gene integration did not negatively influence growth and metabolism of J9U-MP. A real-time monitoring system was established with enhanced green fluorescent protein (EGFP) to track the movement and activity of J9U-MP in environmental remediation. A low-oxygen tolerant system was developed by enhancing oxygen utilization, which makes J9U-MP maintain the MP-mineralizing activity under oxygen-limited conditions. More importantly, efficient mineralization of MP by J9U-MP in high saline wastewater was demonstrated. This study highlights that synthetic biology has opened up new avenues for creating stress-resistant pollutants-mineralizing microbes. Competitive advantages of J9U-MP in high-salinity and low-oxygen environments make this degrader suitable for bioaugmentation of pesticide wastewater.