The invention relates to a coking corrosion inhibitor for an adiponitrile rectification device. The coking corrosion inhibitor comprises the following components: 1%-5% of a dispersing agent, 1%-10% of a quaternaries modifier, 8%-25% of a phosphite ester anti-oxygen reagent, 10%-25% of alcohol and ester compounds and 30%-70% of a compound solvent. The coking corrosion inhibitor provided by the invention can effectively suppress the generation of adiponitrile isomeride ICCP (amino cyano cyclopentane) at the tower bottom, can control ICCP contained in adiponitrile generated by an adiponitrile product tower to be less than 50ppm, can suppress the generation of coking matter in the adiponitrile rectification system, can ensure the stable running of the adiponitrile rectification system and can prolong the operation period of the adiponitrile rectification system.