The invention relates to a washing machine without water between barrels and a control method. The washing machine comprises an outer barrel, an inner barrel, an air chamber and a pressure sensor, wherein the pressure sensor is connected with the air chamber. A plurality of water throwing holes are formed in the upper portion of the inner barrel and close to the edge of the inner barrel, at least one inner barrel drain port is formed in the bottom of the inner barrel, telescopic drain valves capable of plugging the inner barrel drain ports are arranged at the bottom of the outer barrel, an outer barrel drain port is formed in the bottom of the outer barrel and provided with a washing machine drain pipeline, and the air chamber communicated with the inner barrel is arranged on the outer barrel and provided with an air chamber drain port capable of draining water in the air chamber. The washing machine thoroughly drains the water without residual water and is high in drain speed, accurate in water level detection and simple in structure, stay of water flow between the inner barrel and the outer barrel is avoided, dirt is prevented from staining the inner wall of the outer barrel, the residual water in the air chamber is avoided, errors caused by reuse of water level detection are avoided, the residual water is prevented from breeding bacteria in the air chamber, the outer barrel is communicated with the inner barrel through the telescopic drain valves, and line chip blockage is avoided.