The invention discloses a manufacturing method and process device of a reactivated cleaning agent for regeneration of a honeycomb SCR (selective catalytic reduction) denitration catalyst. The deactivated SCR denitration catalyst in the process device is regenerated through the steps of pressurized water spraying, ultrasonic cleaning, secondary pressurized water spraying, acid washing, forced air drying, active component supplementation, secondary forced air drying, step-by-step calcination and the like in sequence. By using (NH4)2SO4 as a main component of an acid washing solution, potential hazards caused by sulfuric acid are avoided, and the economic performance and the safety are realized. The components such as EDTA (ethylene diamine tetraacetic acid) are added into the cleaning agent, and under the chelation of the EDTA and heavy metal elements, the toxic action on the denitration catalyst caused by the heavy metal elements can be well eliminated. According to the process, the denitration activity of the deactivated catalyst can be recovered, and meanwhile, the structural strength of the catalyst can be kept. The process device is simple, suitable for regeneration in hoisting transportation, and high in efficiency. By the promotion of the process, the performance of the regenerated honeycomb SCR catalyst can be improved, the replacement cost of the catalyst is saved, and the process has an important significance on NOX control.