The invention relates to the technical field of medical radio-frequency ablation, and in particular to a large-area discharge ablation device. The large-area discharge ablation device comprises an ablation catheter and a guide tube, wherein an ablation handle is arranged on a guide handle in a sliding mode; the ablation catheter comprises a catheter body; the catheter body comprises a solution cavity; at least two conductive parts, which are used for implementing electric conduction, are arranged at the end, which stretches into a human body, of the catheter body; and radio-frequency current, which is applied to the conductive parts, sequentially passes through one of the conductive parts, human tissues and the other conductive part, so that at least one closed loop is defined; therefore, stress on the ablation catheter can be monitored in an ablation process in real time, and an ablation area can be increased; with the application of an electrical stimulation method, a focus tissue can be searched; and meanwhile, operations can be facilitated.