The invention discloses a continuous production process of a diazo compound. The continuous production process includes the steps that a diazo component sulfuric acid solution is prepared, the diazo component sulfuric acid solution is mixed with nitrosyl sulfuric acid, and the mixed liquid conducts a reaction through a tubular diazotization reactor device and is discharged; the tubular diazotization reactor device comprises two or more sections of tubular reactors which are connected in series, each section of the tubular reactor is provided with an online detection point, a material supplementation point and a product discharging point; all the tubular reactors are sorted according to the flow direction of materials, and each section of the tubular reactor determines the material flow direction according to the detection results at the online detection points. The invention further provides a device for implementing the process. By means of the continuous production process and device of the diazo compound, automated continuous production is achieved, product quality is improved, and the yield is raised; timeliness of product removal is achieved, unnecessary standing time is saved, the production cycle is shortened, and production capacity is improved; meanwhile, generation of waste water, waste gas and solid waste is reduced, and environmental pollution is lowered.