The inhibition effect of 5-nitroindazole on corrosion of copper in 3.0% NaCl solution was investigated via electrochemical tests,scanning electronic microscope(SEM)and theoretical calculations.These studies have revealed that 5-nitroindazole is a mixed-type inhibitor and its inhibition efficiency up to 99% at 0.4 mM inhibitor is obtained.The experiment results of SEM further confirm the excellent inhibition performance of the compound.The quantum chemical calculations and molecular dynamics simulation were conducted to analyze the adsorption mechanism of 5-nitroindazole molecule.