A water draining method of washing machine, wherein the washing machine is an upper-drain type further including a first outer container configured to receive washing water, a first inner container provided within the first outer container, a motor configured to drive the first inner container rotating, a first draining system, which is communicated with the bottom of the first outer container, including a first draining conduit and a draining pump, comprising: initiating a drain cycle, during which keeping the draining pump working at an alternate operation mode until the liquid level within the first outer container decreasing to a preset draining level, wherein the alternate operation mode comprising running and pausing the draining pump alternately; and initiating a spin cycle, during which controlling the motor to drive the first inner container rotating and spinning while keeping the draining pump working at an alternate operation mode, characterized in that the spin cycle further comprising a low-speed spin, the low-speed spin comprising: a. controlling the motor to drive the first inner container spinning at an increasing rotation speed while keeping the draining pump working at the alternate operation mode; wherein the highest rotation speed capable of reaching in the low-speed spin is set as a first rotation speed; b. determining whether an over-suds condition occurs in the washer by detecting the liquid level within the first outer container; if the over-suds condition occurs, then entering into a step c followed; if the over-suds condition does not occur, entering into a de-foaming mode and then back to the step a sequentially; wherein the de-foaming mode comprises: reducing the rotation speed of the first inner container to the distributed rotation speed, and sequentially supplying fresh water into the washer in a period while keeping the draining pump working at the alternate operation mode, c. detecting the rotation speed of the first inner container and determining whether it meets the first rotation speed or not; if the rotation speed reaches the first rotation speed, the low-speed spin ends; if the rotation speed is lower than the first rotation speed, performing the de-foaming mode and back to step a sequentially. initiating a drain cycle, during which keeping the draining pump working at an alternate operation mode until the liquid level within the first outer container decreasing to a preset draining level, wherein the alternate operation mode comprising running and pausing the draining pump alternately; and initiating a spin cycle, during which controlling the motor to drive the first inner container rotating and spinning while keeping the draining pump working at an alternate operation mode, characterized in that the spin cycle further comprising a low-speed spin, the low-speed spin comprising: a. controlling the motor to drive the first inner container spinning at an increasing rotation speed while keeping the draining pump working at the alternate operation mode; wherein the highest rotation speed capable of reaching in the low-speed spin is set as a first rotation speed; b. determining whether an over-suds condition occurs in the washer by detecting the liquid level within the first outer container; if the over-suds condition occurs, then entering into a step c followed; if the over-suds condition does not occur, entering into a de-foaming mode and then back to the step a sequentially; wherein the de-foaming mode comprises: reducing the rotation speed of the first inner container to the distributed rotation speed, and sequentially supplying fresh water into the washer in a period while keeping the draining pump working at the alternate operation mode, c. detecting the rotation speed of the first inner container and determining whether it meets the first rotation speed or not; if the rotation speed reaches the first rotation speed, the low-speed spin ends; if the rotation speed is lower than the first rotation speed, performing the de-foaming mode and back to step a sequentially. a. controlling the motor to drive the first inner container spinning at an increasing rotation speed while keeping the draining pump working at the alternate operation mode; wherein the highest rotation speed capable of reaching in the low-speed spin is set as a first rotation speed; b. determining whether an over-suds condition occurs in the washer by detecting the liquid level within the first outer container; if the over-suds condition occurs, then entering into a step c followed; if the over-suds condition does not occur, entering into a de-foaming mode and then back to the step a sequentially; wherein the de-foaming mode comprises: reducing the rotation speed of the first inner container to the distributed rotation speed, and sequentially supplying fresh water into the washer in a period while keeping the draining pump working at the alternate operation mode, c. detecting the rotation speed of the first inner container and determining whether it meets the first rotation speed or not; if the rotation speed reaches the first rotation speed, the low-speed spin ends; if the rotation speed is lower than the first rotation speed, performing the de-foaming mode and back to step a sequentially.