A water draining device of a washing machine, a washing machine and a control method, cleaning particles (5) for cleaning a tub wall are provided between an inner tub and an outer tub of a washing machine, the cleaning particles (5) are collected into a particle collecting chamber (6) when the water draining device is draining water, and float upwards from a water inlet (12) to be between the inner tub and the outer tub of the washing machine under a buoyancy force during water feeding. The water draining device (1) of a washing machine comprises a drain valve body (11), a water inlet (12) and a water outlet (13), the water inlet (12) is in communication with a water draining outlet (2) of the outer tub of the washing machine, the drain valve body (11) is provided therein with a particle collecting chamber (6) communicating with the water inlet (12), a particle filtering structure (8)is provided between the particle collecting chamber (6) and the water outlet (13), the water draining device (1) further comprises a water/air access mechanism, the particle collecting chamber (6) is provided therein with a port (61) having a communication with the water/air access mechanism, and the water/air access mechanism controls water or air flow into the particle collecting chamber. The water draining device (1) enables all the added cleaning particles (5) to flow upward, thus enabling faster addition of the cleaning particles, further, line debris can be completely discharged during water draining without casuing a blockage.