The invention relates to the technical field of central air conditioners, in particular to a pipeline repairing device for the central air conditioner. A detection device comprises an industrial personal computer, a detection head, a blocking sleeve pipe, a sleeve pipe expulsion device and a detection head moving device, the detection head is connected with the industrial personal computer througha vacuum pipe, the lower end of the detection head is provided with a blocking sleeve pipe sleeve, the sleeve pipe expulsion device is connected to the middle portion of the detection head in a sleeved manner, the upper end of the detection head is further connected with the detection head moving device in a sleeved manner, the repairing device comprises an elastic sleeve pipe, expansion rings and a locking mechanism, two ends of the elastic sleeve pipe are each provided with one expansion ring, the two expansion rings are both connected inside the elastic sleeve pipe in a sleeved manner, andthe locking mechanism is clamped on the two expansion rings. By means of the pipeline repairing device for the central air conditioner, segmented pressure maintaining test performed on the inner portion of a heat exchanging pipe is realized, so that leakage point positions of the inner portion of the heat exchanging pipe are found out, the two expansion rings are driven by the locking mechanism to fix the elastic sleeve pipe inside the heat exchanging pipe, and repairing on the leakage point positions of the heat exchanging pipe is realized.