In this study, the effect of the operating temperature on the removal of high p‐nitrophenol (PNP) concentrations by Fe/Cu/H2O systems has been investigated thoroughly. The results suggest that only a higher operating temperature (>40°C) could significantly improve the removal efficiency of high PNP concentrations (e.g. 10 000 mg/L) by Fe/Cu/H2O systems. Meanwhile, a lower PNP concentration (e.g. 500 mg/L) could be completely removed by Fe/Cu/H2O systems only at 40°C. Furthermore, the interaction between the operating temperature (10–85°C) and other key operating parameters including theoretical Cu mass loading (0–0.89 g Cu/g Fe), Fe/Cu dosage (5–35 g), stirring speed (0–400 rpm), electrolyte (0–50 mmol/L NaCl or Na2SO4), and initial pH (3.–12) was investigated, respectively. In particular, the elevating temperature could decrease theoretical Cu mass loading, Fe/Cu dosage, stirring speed and electrolyte, and abroad the range of initial pH, which could reduce the operating cost of Fe/Cu/H2O systems if the waste‐heating vapor could be used to elevate the operating temperature. According to the results of UV‐Vis spectra, for total organic carbon and chemical oxygen demand, it is clear that the elevating temperature could facilitate mineralization of PNP in an aqueous solution by Fe/Cu/H2O systems. As a result, the operating temperature was a main factor for the removal of pollutants by Fe/Cu/H2O systems.