Objective: A simple, efficient, rapid, sensitive, reproducible, accurate and rapid method was established for the simultaneous determination of 12 nitrophenols in water. Methods: Magnetic Fe₃O₄ nanoparticles loaded with bifunctional octadecylamine functionalized carbon nanotube composites were synthesized by coprecipitation and hydrothermal methods. The sample pretreatment method of QuEChERS was optimized and combined with gas chromatography-mass spectrometry to establish a method for the simultaneous determination of 12 kinds of nitrophenols in water quality. Results: The optimized QuEChERS sample pretreatment method gave the advantages of magnetic nanoparticles and carbon nano materials. Under the control of these conditions, high efficiency of purification of the 12 kinds of nitrophenols in water was found, with shortening the pretreatment time, eliminating matrix interference, and omitting complex operation steps of filtration and centrifugation. The established sample pretreatment method was based on QuEChERS, and the concentration range of 0.05~0.20 μg/mL has a good linear relationship, with the minimum detection concentration of 0.009~0.010 μg/mL, the average recovery ranging from 82.2% to 94.6%, and the relative standard deviation less than 10%. Conclusion: Compared with the traditional technology, the optimized QuEChERS technology has the advantages of simple operation, strong adsorption capacity, low cost and small amount of organic reagent, and can realize the integration of enrichment and separation.