The invention discloses a method for preparing N,N-diethyl-3-pyridine carboxamide. The method comprises the following steps: adding nicotinic acid and dichloromethane into a reaction bottle and dropwise adding oxalyl chloride at the temperature of 0 DEG C; after oxalyl chloride is added dropwise, stirring and reacting at the temperature of 0 DEG C for 0.5-1 hour and reacting at room temperature for 4-6 hours; after the reaction is ended, dropwise adding a sodium hydroxide solution for regulating the pH value of the reaction solution to 7, slowly dropwise adding diethylamine at the temperature of 5 DEG C below zero to 10 DEG C; after diethylamine is added dropwise, reacting at the room temperature for 6-8 hours; after the reaction is finished, adding a sodium carbonate solution, stirring, standing for layering, removing the lower water layer, drying the organic layer, thereby obtaining a crude product of N,N-diethyl-3-pyridine carboxamide; adding the crude product of N,N-diethyl-3-pyridine carboxamide into dichloromethane, discoloring, oxidizing, removing dichloromethane, performing reduced-pressure distillation, thereby obtaining the finished product of N,N-diethyl-3-pyridine carboxamide. The method is low in equipment requirement, slight in environmental pollution and low in danger coefficient and is a synthesis method which is environment-friendly and very suitable for industrial production.