A reduction clutch for positioning an inner tub has an input shaft connected to an output shaft. An input shaft sleeve is connected to an output shaft sleeve. A clutch shaft sleeve slides axially downward to connect to a driving device and slides upward to connect to a fixed disk at one position in the circumferential direction. The positioning of the input shaft sleeve, the output shaft sleeve and an inner tub in the circumferential direction is achieved by the connecting position. A first water drainage hole is arranged at the bottom of the inner tub. An included angle between a protrusion on the upper portion of the clutch shaft sleeve and the first water drainage hole of the inner tub is equal to an included angle between a recess on the fixed disk fitting with the protrusion and the water drainage control mechanism on the outer tub.