The invention discloses a regeneration method of a MnOx/TiO2 based low-temperature denitration catalyst. The regeneration method includes the following steps that high-pressure air is used for purging a catalyst monomer, then the catalyst is impregnated in deionized water under the action of ultrasonic waves to remove impurities and soluble substances, drying is performed, and then the obtained catalyst is put in an activation solution for activation treatment and then is sequentially subjected to microwave drying, calcination in a muffle furnace and ultraviolet irradiation treatment to obtain the regenerated SCR denitration catalyst. By means of the regeneration method, the regeneration problem of the deactivated MnOx/TiO2 based low-temperature denitration catalyst is solved, the MnOx/TiO2 based low-temperature denitration catalyst is applicable to catalysts deactivated to different degrees, and the denitration activity of the obtained regenerated denitration catalyst can be up to 97%. The using amount of the activation solution can be saved. Mn-Ti catalyst sol prepared by adopting a sol-gel method enables active components to be supported firmly, and the denitration effect is improved. In addition, the activity and poisoning resistance capacity of the regenerated catalyst can be improved by adopting the ultraviolet radiation treatment.