The invention relates to a mop cleaning barrel which is used for cleaning a cleaning head arranged at the lower end of a mop. The mop cleaning barrel comprises a cleaning barrel body which allows thecleaning head to be inserted into. The mop cleaning barrel is characterized by further comprising a cleaning water storage barrel, wherein the cleaning barrel body and the clean water storage barrel are independently arranged; the clean water storage barrel comprises a sealed internal space for storing clean water, the internal space is communicated with a supercharging device, and the sealed internal space can be continuously supercharged under action of the supercharging device; a water spraying opening communicated with the internal space is arranged on the clean water storage barrel, and aone-way valve and a switch for driving the one-way valve to be turned on or off are arranged on a communication path between the water spraying opening and the internal space; the water spraying opening faces the cleaning head inserted into the cleaning barrel; after the internal space is supercharged, the switch can drive the one-way valve to be turned on, and clean water can be continuously sprayed from the water spraying opening to continuously clean the cleaning head. Compared with the prior art, the mop cleaning barrel disclosed by the invention has the advantages of ability in continuously providing clean water to clean the cleaning head and convenience in operation.