The invention provides a domestic sewage purification device and method. The device comprises a hydrolysis acidification tank, a membrane aeration bioreactor and a carbon filter tank, wherein the twosides of the top of the hydrolysis acidification tank are connected with a first inlet pipe and a first overflow pipe respectively, the first overflow pipe is connected with a bottom water inlet of the membrane aeration bioreactor, a top water outlet of the membrane aeration bioreactor is connected with a top inlet of one side of the carbon filter tank through a second overflow pipe, and the otherside of the carbon filter tank is provided with a water outlet pipe; the top of the hydrolysis acidification tank is connected with a nitrification liquid return pipe, and the bottom of the hydrolysis acidification tank is connected with a sludge return pipe; the membrane aeration bioreactor is internally provided with a membrane aeration biological reaction mechanism, and a bottom plate of the membrane aeration bioreactor is provided with a heater and a magnetic stirrer; a filter material layer and a supporting layer are arranged in the carbon filter tank, and a backwashing mechanism is arranged at the bottom of the carbon filter tank. The domestic sewage purification device and method have the dual effects of denitrification and dephosphorization, high aeration efficiency, low energy consumption, strong impact load resistance, simple operation and good water outlet quality.