The invention provides a continuous diazotization production process of aromatic amine. The process is as follows: by utilizing a multistage serially connected diazotization reaction kettle, throwing a powdery aromatic amine raw material into a stock bin of a feeding system, integrally weighing the feeding system and the solid raw material through a weighing device, continuously and stably adding the aromatic amine into the diazotization reaction kettle through an automatic feeder, calculating the feeding dosage of the aromatic amine raw material within a unit time through a difference method, continuously and stably adding nitrosyl sulfuric acid and sulfuric acid into the diazotization reaction kettle according to a feeding molar ratio of the aromatic amine, the sulfuric acid and the nitrosyl sulfuric acid of 1:(1-5): (1.01-1.10) through a liquid metering and adjusting device, stirring and controlling the temperature to 0-40 DEG C to carry out a diazotization reaction. By adopting the continuous diazotization production process disclosed by the invention, industrial large-scale production becomes possible, the traditional intermittent dosing method of raw materials is improved, the reaction raw material proportion, the reaction temperature and the reaction time are accurately controlled to improve the diazonium salt yield, stabilize the diazonium salt quality and reduce the color differences between lots.