The invention discloses a dishwasher and control method thereof, wherein, the dishwasher has a filter block detecting device, the dishwasher of the invention comprises a washing slot mounted with a shelf for placing dishes therein; a water collecting slot which is arranged in the washing slot and is used for containing the washing water; a washing pump for pumping the washing water in the water collecting slot; a washing nozzle for injecting the washing water, wherein, a filter for filtering foreign materials contained in the washing water and a soil chamber of a pressure detecting device fordetecting the internal pressure, and under the condition that the detected pressure by the pressure detecting device is larger than the preset pressure, the filter is judged for being in a blocking state.