The invention provides a decoloring recycling device for printing and dyeing wastewater. The device comprises an electric flocculation pond, a settling pond, a filter pond and a water storage pond. The device adopts electrochemical flocculoreaction, physical settling and efficient filtration in a combined manner and is matched with processes of circular treatment of the printing and dyeing wastewater by an online monitoring system, the printing and dyeing wastewater meets the recycling demand. A decoloring recycling method and process for printing and dyeing wastewater of the device is energy-saving and environment-friendly, can decolorize and recycle the wastewater without additionally adding a chemical reagent, can realize online monitoring of the quality of the wastewater, and intelligently selects recycling or circulating treatment according to a monitoring result. The device also has a function of automatically cleaning the filter device and can collect sludge produced in each stage in a centralized manner separately on the basis of guaranteeing repeated use of a water resource for the convenience of treatment in the later period. In addition, the whole set of system provided by the invention is simple and convenient to operate, the device is small in occupied area, and the device can be quickly and flexibly applied behind various primary treatment systems, and has good economical and environmental benefits.